I hope they're not removing the revert option for Classic UI :(

Having an API unable to support two clients (Classic and New) would be embarassing from an engineering POV.

And from an UX POV, it really lacks empathy (or realism) to assume that the same exact UI will be useful/pleasant to literally 1 billion users. There are all kind of reasons why a given person might prefer UI a to b (a being older having nothing to do).

As you reach more humans, you have to embrace diversity. The views from a handful of hipster designers in SF shouldn't irreversibly impact how the rest of the world interacts with their computers.