I think the fact that he lied, and it led to the negative feedback and flag against him means that this Twitter mass reply bot could also be a lie as well. Or I have also noticed a number of replies that get shadow-banned especially due to spamming or continued violation of x community guidelines.
It should be so. However, since Musk took over Twitter and established X, moderation on that network has become much more tolerant of spam. That is, it does not cause a quick suspension of spam accounts, especially if the account has a blue badge.
What is unlikely is that AI bots like the one offered by the OP have minimal efficiency.
Correct, accounts need warmup.