The discussion revolves around whether the 3.1.0.beta3 search improvements require a reindex. mcdanlj initiates the conversation, citing uncertainty about the status of prioritize_exact_search_title_match and whether a reindex is necessary. MarcP bumps the topic, seeking clarification.
mcdanlj shares their experience of running rake search:reindex, which took over 16 minutes to complete. sam provides a definitive answer, stating that prioritize_exact_search_title_match is now default true and the index version has been bumped to version 5. This means that the system will automatically reindex topics and posts in the background every 2 hours, making manual reindexing unnecessary.
The 3.1.0.beta3: Search optimizations, Resizable chat drawer, New API scopes, and more announcement references Refinements to search being tested on meta but it’s not clear what the current status is.
it looks like prioritize_exact_search_title_match is still hidden. Is this something we should expect to use? Are we supposed to run rake search:reindex after deploy as I see in this comment in the thread?
I’m not sure I know what to expect to do to after doing the update.
Had this bookmarked and would’ve expected a reply by now as this is a good question.
Just posting to bump this topic up 
I assumed that it’s necessary and ran it on one of my sites so far. It took over 16 minutes to complete in that case.
I was mostly hoping that we’d get a definitive answer before running it on the other sites I maintain, but oh well, guess I’ll do that. 
No and no 
We amended the default prioritize_exact_search_title_match is now default true.
We also bumped up our index version to version 5.
This means that every 2 hours 10,000 topics and 20,000 of the newest posts with an old index version will be reindexed.
You can rush the process by running rake search:reindex but there is no need really, it will happen automatically in the background anyway. (it probably did already for most)