There is no reason for a bot to be able to access or post on federated social networks if the goal is to make social media humane.
For this reason, bots should be heavily disallowed from posting content to or accessing content from federated social media.
“Stealing” posts is a good argument against bots as well. As a user if, every time I went to post, my post was already “taken” then I’d be less likely to post in the future.
Although technically that’s true even without bots.
I do think limiting in general how often any one account can post makes sense, so I would extend that same rule to bots.
For “good” bots we could even request that they wait 24 hours before posting something new. (Of course if the rules are too strict we’ll just have bad bots and that defeats the point of having bot rules.)