From https://tex.stackexchange.com/privileges/set-bounties – When does a bounty expire?
If you do not award the bounty within 24 hours of the bounty period
ending, half the bounty value will be automatically be awarded to the
top voted answer posted after the bounty start, provided it has a
score of at least 2. If no new answer matches this ...
Everybody sees the same question that is poked (maximum of one such question per hour), so it's independent of the user. It is dependent on the question though, and as mentioned in the Community user profile - old and unanswered. More specifically, questions eligible for bumping have gone at least 30 days with no activity, have at least one answer scoring 0 ...
Exactly as T. Verron says, your edit was rejected because it was conflicting with another edit by the OP, which overpowers suggested edits.
What is strange, IMHO, that the OP's edit is actually verbatim the same as your edit.
Therefore another possibility is that the OP actually hit "Reject and Edit" in the review. However, his edit review is not in the ...
The Community user periodically bumps unanswered questions to get more eyeballs on them.
There (probably) are other ways a question could get "bumped" by a regular user and yet look like there are no changes. One way would be for someone to post a spam answer that's then removed. If/when you see other examples, let me know and I'll see what happened with ...
The rule for Community here is simple: questions without upvoted answers are possible candidates for bumping. In the question you link, the answer has received no upvotes, so it's not regarded as answered: the entire idea of StackOverflow is that answers are important to more than just the person who asks the question.
Please remember that he is not exactly a bot. His competences are much more than actively doing something. Basically when the system needs to put a name to an action that has no name associated, it's this user that gets the action.
As for "bots": the name is ridiculous, and certainly below the level of professionalism that StackExchange aims at.
I think that an automatism sometimes could be dangerous.
All question having a self-answer should be marked as "answered".
It may happen that the OP answers with a workaround, but s/he still looking for something better. See here, for example:
Diagonal arrows consisting of smaller arrows in xymatrix package.
All question having one (or more) answer(s) ...