Locking the thread not be a good decision and just like you said if the thread becomes a spam ground and no update from the admin it will be better to get it locked. But if the admin will appoint a representative to answer people around here.
You are right that locking the thread won't be a wise decision and also if no representative appears on here still community will take part on the conversation which will keep active this thread. To avoid spam thread creator could do the same which can a user of the forum can do.
If it is noticed that there is a problem here but the users will lose an area from where they have these problems but they can post here but anyway the problem they have here if they are under their control here. Don't know if it's going to be unlocked but here again in the future but here's the latest version for sure