Ah... my mistake then. I should have counted on the gating, since it’s a key Blizzard strategy these days.
That would change everything then. It could actually kill Classic faster than I expected if people are forced to wait longer than their rate of progression.
Being Blizzard, they will likely use this as a tool to pad dead spots in retail (example: live patch in Jan, Classic in March, live again in May, Classic again in July, etc.). This might not work to the desired effect however, since a lot of the players will stick to only one version of the game. It could end up angering both playerbases who are getting content at slower paces than they feel is reasonable.
It will be interesting to watch unfold.