am181d
Adventurer
...and campaigns that run from 1-20 are in the minority.
This is the relevant point. If a very small percentage of players are using certain level ranges, it's incumbent on the designers to adjust those ranges to make them more usable. If most people only play 10-12 levels, then this won't impact them at all. If these changes make additional levels play better for the vast majority of players, that's a broad win.