I used to get a lot of spambot followers, but that has ceased entirely in the past year. I would say the bot problem is no longer that relevant at the moment, but rather people posting AI replies are.
But if it's blanket rejecting certain signups based on identity, that suggests the company is interested in censorship and echo chambers, which means who knows what other dark patterns and less-detectable bot nets it has behind the scenes.
Doesn't seem worth it imo, except maybe for people who want their opinion echoed back to them (as well as other momentum that takes time to dissipate).