BC and FC are fine. It is the MC that will become rather weird. I wonder if they're going to rename MC to BC (or FC, depending on the gear they're being obtained from) 4 and add in a new BC and FC 5?

I have long been confused by game developers putting in an item that is meant to be at the current pinnacle, but giving it a name indicative that it is THE pinnacle, there is nothing better, when they know that a new expansion, already in the works, will supercede the current ultimate item.