This is an interesting question and with the baby and his/her gender status, CNN reported that the baby
was born in British Columbia, "outside the medical system," and did not undergo a genital inspection after birth, campaign group Gender Free I.D. Coalition said in a statement.
There seems to be no clinical consensus on any psychological effects of not being treated as either male or female, and as the case of this baby seems to be unique and the world's first according to many reports, in the sense of the fact that the baby has not been given an official gender status, there will be no information on any potential future psychological effects to this baby.
Before I answer the question, I will start with a commentary on the gender definitions often used for those who are "genderless" at birth.
There are many different names given to gender identities which could be used to genderise the baby you mentioned (Searyl Atli). They include but are not limited to:
Hermaphrodite (not generally used in modern times),
People born "genderless" were previously referred to as hermaphrodites, "congenital eunuchs", or even congenitally "frigid". Such terms have fallen out of favour; in particular, the term "hermaphrodite" is considered to be misleading, stigmatising, and scientifically specious.
There are plenty of well known people who were born without a specific gender (Non-Binary and Intersex) including a human rights activist. Ruth Baldacchino has a "non-binary" gender identity, and describes the Maltese Gender Identity, Gender Expression and Sex Characteristics Act as providing
freedom to an individual to develop, establish and express their gender, rather than having the State or the medical professionals deciding that. In other words, ... to be allowed to determine what identity fits ... best and how ... to embody that identity.
Human rights institutions are placing increasing scrutiny on medical practices and issues of discrimination against intersex people.
Rationale behind medical intervention
According to Wikipedia,
Medical interventions take place to address physical health concerns, and psychosocial risks. Both types of rationale are the subject of debate, particularly as the consequences of surgical (and many hormonal) interventions are lifelong and irreversible. Questions regarding physical health include accurately assessing risk levels, necessity and timing. Psychosocial rationales are particularly susceptible to questions of necessity as they reflect social and cultural concerns.
Medical description of intersex traits as disorders of sex development has been controversial since the label was introduced in 2006 (Lee, et al., 2006). The DSM-5 included a change from using Gender Identity Disorder to Gender Dysphoria. This revised code now specifically includes intersex people who do not identify with their sex assigned at birth, using the language of Disorders of Sex Development, and this move was criticised by intersex advocacy groups in Australia and New Zealand (Kraus, 2015).
There remains no clinical consensus about an evidence base, surgical timing, necessity, type of surgical intervention, and degree of difference warranting intervention (Lee, et al., 2016)(Mouriquand, et al., 2016)(Creighton, et al., 2011). Such surgeries are the subject of significant contention due to consequences that include trauma, impact on sexual function and sensation, and violation of rights to physical and mental integrity (OHCHR, 2016).
In fact it seems that the opposite is true. Whilst it is often believed that it is essential for gender assignment surgery at or near birth, medicalisation and stigmatisation of intersex people result in significant trauma and mental health concerns (IIF, 2013). Whilst the IIF at the same meeting stated that
[To ensure] the bodily integrity and well-being of intersex people, autonomous non-pathologising psycho-social and peer support [should] be available to intersex people throughout their life (as self-required), as well as to parents and/or care providers.
As for the case of Searyl Atli Doty, there will be no information on any potential future psychological effects to this baby for reasons stated in my short answer.
Having said that, gender is an important part of a person's sense of identification within society. UCL (University College London) has an LGBT Student Support page which states
Gender Identity is a person's individual sense of femaleness or maleness. It is also, to some degree, a social construction that categorises certain behaviours into male and female roles. Gender identity conflicts can stem from an individual's gender indentity not matching their biological sex, an individual's gender identity being neither completely male nor female, or an individual's biological sex not being uniquely male or female.
hence the reason why there are so many different gender identities and sexualities within the LGBTQIA community.
Because of the way society frames everyone based on gender, it seems important to have a gender identity, so aside from the possible legal issues such as
which set of toilets is Searyl going to be legally allowed to use?
it will be interesting to the field of Psychology, how being registered and raised without a gender would affect Searyl's wellbeing.
Creighton, S. M., et al., 2011. Childhood surgery for ambiguous genitalia: glimpses of practice changes or more of the same? Psychology & Sexuality 5(1): pp. 34—43
IIF, 2013. The statement of the Third International Intersex Forum, December 2013 [Online]
Available at: http://intersexday.org/en/third-international-intersex-forum
Kraus, C., 2015. Classifying Intersex in DSM-5: Critical Reflections on Gender Dysphoria. Archives of Sexual Behavior 44(5): pp. 1147—1163
Lee, P. A., et al., 2006. Consensus Statement on Management of Intersex Disorders. Pediatrics 18(2)
DOI: 10.1542/peds.2006-0738 PMID: 16882788
Lee, P. A., et al., 2016. Global Disorders of Sex Development Update since 2006: Perceptions, Approach and Care. Hormone Research in Paediatrics 85: pp. 158—180
Mouriquand, P. D. E., et al., 2016. Surgery in disorders of sex development (DSD) with a gender issue: If (why), when, and how? Pediatric Urology 12(3): pp. 139—149
OHCHR, 2016. End violence and harmful medical practices on intersex children and adults, UN and regional experts urge Intersex Awareness Day – Wednesday 26 October 2016 [Online]
Available at: http://www.ohchr.org/EN/NewsEvents/Pages/DisplayNews.aspx?NewsID=20739&LangID=E