The real question is if they’ll actually call him Plageuis, or if he’ll just make some vague comment about having trained Palpatine.
Either way, I won’t really mind if it’s dealt with in the proper fashion.
I’m cool with a vague reference to having trained Palpatine (in fact, the idea of an ancient Sith lord, the grand-daddy of them all, is kinda cool), but anything that directly links the new trilogy to the prequels (eg. specifically calling him Darth Plaguis) will make me cry.