You forgot to report the bug.
I followed the instructions and deleted the 1.16.json files, it didn't work but it's not too big of a deal, and I was looking at newly extracted 1.16 files.
This is working as intended as hitboxes used to be a way to find invisible players, all though this is more of a suggestion than a bug I agree with you that non player entities should have hitboxes shown when invisible.
I am aware that they are allowed to block names for undisclosed reasons, but these aren't necessarily blocked, just unintentionally soft locked due to an overlook.