[ImmNinjaxD]

But people should give serious reason why it should be unlocked

Yeah, that's what I meant, just like if you report a post/thread where you need to specify a reason.

OR instead of just unlocking the thread the person that tries to post something it auto PMs the creator of the thread optional thing if threads creator would have option himself to unlock the thread he has created ages ago for someone to post if the person who PM'ed him gave serious reason. So that wouldn't overload Mods work to unlock threads requested by people.

This would be fine, but if the "request unlock" plugin/whatever remains where threads are locked by staff purposefully, it could potentially be exploited to have a user unlock a thread they owned that staff determined over. It would probably just be safer to leave it to the mods, but it all depends on if and how this happens.