LOL The red dragons joining the Horde? Who comes up with this shit?
After all that went down in the second war, Alexstrasza had an uneasy relationship with the Horde at best... and that was before they accepted Dragonmaw into their ranks in Legion.
BASIC CAMPFIRE for WARCHIEF UK Prime Minister!
I mean if wild speculation isn't the same thing as confirmed I don't know what is.
I think Alexstrasza goes to the Alliance because of the past Events during Warcraft 2 with the Horde. As for Bolvar he would probably play a role in the horde with sylvanas. Who knows what's going to happen.