Seriously, don't make a second server. Instance all the zones like the newb zones. Even raid mobs/raid zones. Why not take a page from FFXI's book and have turn in items to spawn (create an instance of) raid mobs/zones? There are multiple ways to implement these items. You could have them drop off mobs that give exp. You could have them drop off mobs that are a specific con (white+ or whatever) or are a specific level. You could have them cost a large amount of plat. You could have them come from completing challenges. Whatever. But you gotta learn from the previous progression servers; all this "original" competition (that isn't actually original) just creates a toxic community at the high end. What positives will this plan sacrifice? I'm not sure. You still have a challenge to get to raid mobs. You still have a time investment (if implemented properly). You still have a sense of achievement. It'll have to be tuned, of course, but we have so much freaking time in classic to get it right (seriously, why didn't we start with Kunark again?). Maybe this isn't the right plan. Whatever. But it's better than just doing nothing. Come up with something; this server is your current cash cow -- so feed it well and it will produce well.
Yes we need a second server. It will be provided or someone will be fired for incompetence. Instancing solves nothing about too many people logging in and 12,000 people wanting to play on one server. Just make the second server faster progression.
To be fair, 3 months ago they didn't have the /pickZone stuff worked out (it's just now starting to work well). Now they can build on that.
Instancing is the easy way out. We don't need an instanced game. We need either an increased server size, or another server. Heck, I'm feeling greedy. I want both! Progression Servers are immensely popular, as we can all see. It is the only reason I'm playing again TBH.
They had that idea 3 months ago and knew they were doing it though. Doesn't change their argument of "we feel strongly that instancing raids is not classic." They can do it sure... they do not want to even discuss it because of the above however...