Season 7 - 'Some' spoilers needed

I'm one of those (probably many) fans who is waiting to see how S7 shapes up, without almost all the old cast, before giving it a try. Just curious- is there a good explanation for why the cast is gone? Are the new characters interesting? Is there any indication that our old favorites (will) get their HEA? I'm most interested in CapSwan! Spoilers welcome!