Yeah. I see your point and it is def’ a slippery slope in terms of mixing the two player bases, esp with unobtainable mounts, pets, and achievements.
i’ve been paying attention to retail levels in conjunction with classic levels. with cata, the max level is only 85. while the current max in DF is 70. War Within will see an increase to 80 during the same time classic cata is happening. Pandaria sees an increase to 90, and under assumption, WoW Midnight will increase to 90 as well, making them the same level. If they end up doing what I originally speculated, the characters will be the same level wise going into the last of the 3 world saga expansions, having people transfer over to retail and then starting over classic after the last titan, and or during the second part of that expansion. I also believe they will do a level squish again in wow during this time. Again, this is just my own personal opinion.
I just really don’t think they’re gonna go to WOD. The only reason I could see it happening is because of Legion and how well it did for Blizzard and how good it was of an expansion. MOP was really the last expansion that had a lot of players and an influx of players that came in at the time (funny enough I actually hate MOP).