The forum should allow an OP to close a thread when the OP has sufficient information and don't need any further updates any more. The technology may have changed, the legal requirements may have evolved, the equipment may be outdated, the economics may have reformed. The closed thread can be searched as a reference, but no need to beat the horse to death again after it's already dead.
If anyone wants to chime in for a closed thread, a new thread can be established. We have a thread here for nothing. That's where it belongs.
The ability to manage threads is not, nor should it be a user option/function. When the site team determines a thread no longer has value for the majority of users the we take the appropriate action for the thread.