Are you saying you want PoCs that trigger a crash from the use-after-free or you would only be satisfied by full on RCE PoCs?
1) If it is actually a UAF or if there is some other mechanism missing from the context that prevents UAF. 2) The category and severity of the vulnerability. Is it even a DoS, RCE, or is the only impact causing a thread to segfault?
This is all part of the standard vulnerability research process. I'm honestly surprised it got merged in without a PoC, although with high profile projects even the suggestion of a vulnerability in code that can clearly be improved will probably end up getting merged.
I'm curious which sector of infosec you're referring to in which vulnerability researchers are not required to provide proofs of concept? Maybe internal product VR where there is already an established trust?