Deos discourse still bump the topic if first post in a topic is edited via REST API and the parameter bypass_bump is false?
the answer is no, however for my script it deosn’t matter because without --time-only-dedupe , a location change creates a new topic which obviously gets bumped in latest 
I noticed the recent request specs added in FEATURE: Add bypass_bump parameter to post update API by ZogStriP · Pull Request #36976 · discourse/discourse · GitHub explicitly cover bypass_bump being omitted vs set to false.
In particular, the bumping asserted there is for wiki posts, which makes sense given their existing exception, and helped clarify that bypass_bump=false is “allow default behaviour” rather than a positive bump signal.
That aligns with my reading that for non-wiki posts, false is effectively non-actionable under the current “no bump on edit” behaviour.