I really hope ruffalo wasnt lying and they are in Endgame. Cant wait to see how they tie into things.

Hela's coming back?

"Confirmed" is a strong word that gets thrown around too lightly too often. Mark Ruffalo mentioned in late 2017, during the time they were filming Endgame, that he had just worked with Tilda Swinton and Cate Blanchett in a film. He didn't specify which, but fans worked out the only film that makes sense is Endgame. Then producer Michael Grillo recently mentioned having had problems scheduling for filming Endgame with so many different actors, including mentioning having Tilda Swinton for 1 day.

So yes, it sounds like Tilda Swinton will appear as the Ancient One in some capacity. And perhaps also Cate Blanchett as Hela (though who knows, maybe Mark was referring to having just been in Thor: Ragnarok with her). With the appearance of Crossbones as well, as revealed by Frank Grillo, in some sort of "flashback"-type thing (he may not be 100% truthful in saying "flashback" or may not even know with certainty himself due to the secrecy of the project, but I believe it isn't just present day resurrection stuff), it looks like there will be the reappearances of a few characters due to whatever weird shenanigans are going on in Endgame, be it B.A.R.F. or reality/dimension/time stuff.

But it's not confirmed. Neither of these people are officially part of the cast, so it's not confirmed.