If you look at www.ArgentArchives.org
That is a role playing portal for the Argent Dawn realm (server) community.
So if someone that would want to watch those events accour on their server, that would not be possible and limited on how many could be in same group or raid, just to be at the same place at the same time as the place A is in fact a instance\server\randomness.
It's almost like joining a LFR or Random Dungeon in World of Warcraft, just you do it everytime you enter a new city\town\place as it changes from "Riverwood 0001" "Riverwood 0002" etc.
I've played and RPed on Argent Dawn.
There is very little RP at all.
I fail to see the point you are making. If making an event it is not hard to say "We're meeting at the park" and then add "RP channel" at the end of it on a forum post. As a matter of fact I guarantee you'll see so many more RPers than you've ever seen that it'll make your head spin.
A flaw I can pick out is what you've said yourself, it would not be possible to see random RP happening on another channel. The problem in that logic is that it's *worse* in games with hard server locks that you can't switch. What if I'm on Argent Dawn missing amazing RP on Moonguard? I'll never know, and I'll never see it. Even if I did, I lack a character. You're really boned there, because you couldn't switch a button to change instantly.
Also, what if there's only *1* or *2* RP channels? We don't know how many there will be, but it probably won't be as debilitating as you're making it sound.