Is it ok to ask for more info on why a ticket got resolved the way it did?
I just would want to have more info or more like a reason why something got resolved the way it did to be able to decide better on my own.

Also how should I do it.
Specifically I requested a tag lock and wanted to know if there is a reason behind it or just a subjective decision. I'll not question the decision but just would like to know.

Without any context, it is probably OK to ask for such. Preferably kindly, and if it was done through ticket then you could reply to the ticket's DMail, or make a new DMail to the responder specifically to ask for clarification.

From my experience, no matter what happens, even when stuff gets rejected or no action is taken, the ticket is always marked as "resolved". I think it may be an incomplete part of the site.