IT is hard to say what would happen. As even with discord, some of our allience cannot meet up, due to drop outs, work and other such things.
For me, all the raids are happening while i am asleep or at work. So a solo raid option would be nice, but as i know what it feels like to be put to the side, if only because of time zones, i would be more willing to help others.
So we might see a little bit of both, some top players playing by themselves, to avoid the annoyances, others reaching out to help friends, and even other alliances to being their alpha jounrey.
I have one friend who heads an alliance who is not ready for raids, but so is no one in the allience. IF i could help them, then i could give them and the alliance the boosts it needs to push forward into the harder raids.