This sounds like very interesting world building. Honestly, injecting mew life into Apocalypse and Sinister is one of this era's biggest achievements.
Can't wait to pick up my issue this weekend. Though I will probably stick to the Hickman only issues while the singles are coming out.
Yes, at one point the likes of Emma, the Hellfire Club, Nimrod, Sinister, Shadow King, Proteus, etc. were all brand new OCs. The X-Men became what they are by introducing newer threats.