I have not seen it yet but I am not sure I have seen any huge player options even in SF2 so I would be sus if this would let you start at huge. I suspect if you are already large it wouldn't do anything or possibly just the +5 ft reach as some large races don't get that automatically.
I would second that. PF2e just finally allowed playing as Large creatures without punishing you with clumsy 1, though they allowed it on the condition that you don't gain any reach advantage, except through feats. That seems to be carrying over into Starfinder 2e so, RAI, I would say Large is their limit at the moment until/unless they put some thought into handling potential balance issues of allowing Huge PCs.
Currently I think they are just allowing some ancestries to have stances that give increased reach while wielding a 2-handed melee weapon (mostly large ancestries but, funnily enough, leshy had it first. XD) so it's interesting to see if there is a new feat (i.e. Hulking Corpsefolk) that simply gives an unconditional reach increase.
I would say just ask your GM though. If you really want to play it, I think most things can be allowed so long as they don't cause any problems or balance issues. Especially if everybody is having fun with them. :)