Back before queues drew from the whole datacentre they still worked just fine. You're still going to have more players available now than you did then.

Raiding is a different story but even then, statics existed and progressed just fine before cross-world PF.

Is it going to require a lot of shifting? Yes. Is that good? Not always. Is it easy? Not at all. But I've been dealing with increasing "paused queue timers" because there's no instance space available much more lately, and I remember the absolute vitriol of the entire community over Pipin and Raubahn Savage. While the "SE is so cheap and just does everything the easy way" meme may be popular, they're not so stupid as to do something like this the wrong way if there's an easier, viable method like everybody here somehow "knows" there is.

And hosting an additional physical server with the amount of power, space, and bandwidth it generates isn't anywhere near as "cheap" as some may think it is. We're talking thousands if not hundreds of thousands of Fat Cat purchases, here.