As someone who knows next to nothing about the vtuber scene, I'm the wrong person to comment...but I'm gonna talk out my ass anyway:
I would think the anonymity of being a vtuber would allow them to date freely (but secretly) unlike actual idols and idol adjacents like seiyuus.
I could see them being more open about having a same sex relationship than a straight one though because of what you said about people fuming.
Mostly throwing this out there so people that actually know about the vtuber scene can come correct me.
lol yeah i wouldn't be surprised if the 'popular' ones also did' fake' relationships/only 'flirted' on stream with other ppl, other than the ones that play the 'mommy/onee-chan types' in a platonic way versus a thirst-trap way lol
But i can imagine with all the 'retirements', other than standard contracts only lasting a few years that some companies would be harsh, i mean in japan since there's already similar stuff, but idk if i'd trust some western companies that are for 'vtubers' versus just content creators in general or just getting money from twitch or so lol
I imagine japan can't get as 'political', one got backlash? for talking about hong kong or taiwan or so. Meanwhile you see an 'american' youtuber like nux joking about getting 'cancelled' every other vid but still uploads vids pretty consistently lol
although without going into any details, i can totally imagine some stay at home/retired mom/house wife or like an office worker streaming on the weekends and just shit talking ppl they know in a cathartic way because it's anonymous lol
And ASMR isn't inherently sexual but imagine for the more lewd Vtubers doing moaning requests or so and the walls are thin for all the apartment neighbors to hear lol XD