Squarp has setup the forum so that old topics auto-close (after 21 days of last reply) - I think to stop necroposting, since alot of older threads are based on issues/experiences based on older firmware.
also, if a post has not been replied to in 21 days (unusual) , its likely the OP already had moved on… unlikely they are still waiting 3 weeks later for a reply 
so its better, to have fresh discussion, referring to how the firmware is now - you can of course always refer back to , and quote comments from older threads where relevant.
finally, there generally squarp wanted to encourage users to contact them directly via the contact form for feature requests and bugs - so they get information directly from the ‘horses mouth’.
iirc, they closed some topic that were about features requests, or bugs that had been fixed
but I think most locked topics I see are closed by the auto close 21 day rule.