Threads can be bumped many months later. But if a thread is just spam bumped and no fresh content is added to carry on the discussion then it does risk a lock.
Each thread is dealt with on a thread by thread basis. It's not a blanket lock due to a bump 2-3 months later if someone adds content to carry on or refresh the topic.
Comprehensive Account Security
I've left advice on said thread. So have to leave it for now. It will be checked on every now and then. If we notice nothing happening as in new or refreshed content then I'll pass it along for a Jagex review.
Comprehensive Account Security