Names are all over the place.
Even before DIS, there were numerous Intrepids, Challengers, Constellations, Endeavours, Farraguts, and so on.
Now there's a Constitution, without a -A or -B or whatever, a Armstrong - and I really doubt it took until 3189 to get to Neil Armstrong - while the Voyager is in its -J and there's a -M.
Furthermore, there's a Nog, no supplementary letter, it takes this long to get a ship about the first Ferengi officer in Starfleet? Not something in the 2400s or 2500s?
Where does the -A, -B, -C, thing come from, anyway? Or even -II, -III, -2, -3, etc? I don't see much of it in our reality. Enterprise, Enterprise, and Enterprise are denoted by CV-6, CVN-65, CVN-80, for example. Dreadnought doesn't even get that until S101 and whatever the new one gets. I don't hate it, mind, just interested.