I have no idea who that is.
Sylvester Apollo Bear. Sylvester Bear. Okay. I can't even really comment on this. I get the instant image of a bear wearing a party head celebrating New Year's Eve.
If they want to raise him genderfluid why did he get such a hyper-masculine name? They basically failed in this from day one. I don't think anyone should force gender stereotypes upon children.
However, I feel like it would be much easier for most kids to just be raised as the sex they had from birth (without the girls play with dolls and boys with car stereotypes, just let them play with and wear what they want) and being assured that if they didn't feel like that sex they could change it than raising someone gender fluid. I feel like the constant comments and questions and confusions caused by that would be way more stressful than being raised as one gender (in terms of using "he" or "she" and not "they") and switching at a certain point.