This is an answer from mprep why he locked your 2 threads but I don't see any rule in
Unofficial list of (official) Bitcointalk.org rules, guidelines, FAQ that there is a restriction that does not allow to make new threads (I could be wrong because they are unofficial ones and everything can be changed or decided by admins or moderators).
Your threads were locked due to one of them being a campaign to incentivize posting in a specific thread and the other - the target thread of said campaign. Incentivizing posting in threads outside Games and Rounds is prohibited. As such, both threads will remain locked.