I'm not saying that it's non-canonical, but I'm saying that from the POV of the general Mundaner (non-nerd folk) audience's POV who don't watch things like Rebels, these elements don't mean anything to them.
This is a fair point. If Luke has been training Rey, then it means that there are at the very least two Jedi in existence.
But the Last Jedi won't suck nearly as much as the Last Knight. None of the Star Wars cinematic movies suck like the Transformers movies do. None of them.
<insert.1000.word.explanation>