Yes, extremely logical to keep it on ptr for a month when theres not a soul playing on ptr for 99% of the duration already.
Keeping things on the ptr for a month because every 100 years a patch gets sligtly changed before going to live is even more of a joke than letting live in a terrible state for multiple months.
PTR only exists so people talk about the patch when it hits ptr and then talk again about it when it hits live, so blizzard gets the media attention (youtube/twitch/etc…) of 2 patches for the prize of 1.