I've seen this answered for Stash but not using bitbucket:
Since the migration from FishEye/Crucible, developers can now check in without an issue key, and of course that means that they are 
First to double check that this is intended functionality, and I haven't missed an option somwhere?
Assuming that's the case...
I see you can add hooks on a per repository basis (currently one is defined, presumably the connection to JIRA)
I saw from the stash question that using hooks is problematic because it can reject the push but not the original commit ... but honestly I don't care, if someone tries to check in without an issue key then it's their problem to sort out the mess!
Any ideas? If you can add extensions to egit to enforce it there, that would work too (but I couldn't see anyway to accomplish this)
Thanks for any help anyone can provide!