This started out as a post about server-naming {kind of}, but midway through it, I realized it would be superfluous and instead, realized that there might be a better way to go around the original idea.
It's been established that CoT will be running in a single-server environment, with free movement between instances. Now, I'm not sure if the instance identification will be numeric like CO or STO do it, but if that's the plan, I'd like to suggest an alternative - names. Rather than assigning a number to an instance, each time one is spawned, give it a randomly selected, short and commonly used codeword. So rather than saying "I'm waiting for you at Waterfront 12", it could be "Waterfront Blue" and a player could simply use a command to phase into that instance.
As you said we know CoT will be a single "virtual server" environment. But there's no guarantee they'll implement it with player selectable "instances" that we'll be able to choose from or even be aware of.
For example if they handle it like ESO all of the instancing/phasing will happen "behind the scenes" with players having no direct knowledge or ability to switch between any specifically labeled instance. Obviously there are pros and cons for each type of single-server implementation - just making the point that there are many ways CoT might organize itself that aren't like how CO and STO did it.
CoH player from April 25, 2004 to November 30, 2012
[IMG=400x225]https://i.imgur.com/NHUthWM.jpeg[/IMG]
Just out of curiosity, if you can't actively switch between instances how does ESO handle the situation where you are trying to meet up with some other characters who happen to be on a different instance?
Spurn all ye kindle.