When the accounts get blocked for spam, probably.

Probably not often. If the bot script is written in an even vaguely maintainable way, those links should be all variables even if they never really change. Hardcoding the links would be bad practice (even if running a seemingly pointless spam bot is rather bad practice on its own lol)

I’ve seen a handful of different links in those spots. I assume that they get banned or delete or whatever once they get enough reports made on them for being spam/ a scam.