The problem is there are 2 categories. Microwave safe just means it won’t explode, or throw sparks. The other type sorely lacks a name still. It’s the stuff that is transparent to microwaves and so won’t heat up at all, except for heat transfer from the food.
The basic rule is that you can say what you want (and people can call you what they want for it!).
It would be polite to self moderate to an extent. No point getting the instance owners in to legal hot water. That’s a massively higher bar than Reddit has set however. Chatting about and admiring Luigi is completely fine.