From that statement last October by Mohan_G… it’s highly doubtful its a bug. He straight up said:
So my assumption is exactly what you have explained via your comparison of what happens (or rather NOT) in Notepad, and exactly what I referred to in the thread title I posted at the Symantec forum… but if you’re correct in your assertion of how Notepad relates to the building of that menu, then it seems pretty clear they’re somehow explicitly blocking apps that aren’t Explorer. So I’m guessing Mohan_G meant EXACTLY what he said - and Symantec owes it’s users an explanation.
I only threw out some other non-discriminatory possibilities in that thread because I don’t actually “know”, and because Pierre-Philippe here made reference to someone telling him that they’re using some newer method. But as he didn’t cite a forum thread and I couldn’t find it when I searched so didn’t know who even made that claim. But I actually just found his post and am chiming in there as well.