Included a screenshot of Verg's own words, as a lot of the things posted here imply to me some people think the rumour is a single base rumour.
1.) The most confident lead he has only states that Smash 5 will include Ridley as a newcomer with some Smash 4 assets.
2.) Ontop of this, all characters come back, including Ice Climbers and the new Simon Belmont. This source specifies Ridley being revealed at E3.
3.) Apparently there's a third source unlisted that supports the second (but I think it's probably bull tbh)
Regardless of your belief in cuts (I really think the second leak may have a lot of holes because of this), the first and "most reliable source" only states that our boy is getting in, that it's Bandai-Namco, and that it reuses assets.
------------------------------------------------------------------------------
I don't fully believe the second leak; it plays it safe with IC's, goes off of the first, and includes a newcomer I really can't see coming (due to the parent company's rep recently). I could be completely wrong, but the second one just seems to also go off earlier posts (I believe their on ResetEra) where the mods talked about Smash 5 including Inklings and Ridley (it may not have even been ResetEra, I'm making a guess).
The only thing I'm hopeful and sort of convincing myself of is that Ridley's chances are unironically possibly the highest they will ever be for inclusion; he's wanted, he's relevant, and there's new hardware. If he's going to become a newcomer, I feel like this could be his final chance unless Metroid Prime 4 brings Metroid back into more recent releases.
As for E3, I think that's his only chance as well; Sakurai knows how much people want him, so if we don't see him in 17 days (Nintendo's E3), I think we're doomed.