I just hope Dormammu has a proper role. The whole point of him and Umar is that unlike the rest of the Faltine they disregarded the "being of pure energy" state they had ascended to and became physical beings to have fun (conquer, kill, etc) in the material world. Him being a floating head shouldn't be the only way he appears in the MCU. Bringing Mads back as his avatar would be a good way to reuse him. As for Clea, if they're building up to the Incursions they could merge her with the Black Swan(s) but I think it's unlikely. My theory is that by the time of DS3 he'll start trying to assemble his own Illuminati. He'll track down the MCU Reed, Boltagon, and Xavier, but then it's up in the air for the rest as Namor isn't an established character and has no real reason to be part of such a team.
Concerning the other two, that Carter wasn't What If Peggy so she could return in some live action thing. As for Krasinski, who knows. Maybe he'll be the main MCU Reed going forward. Loki's variants are played by different people, same with the Parkers, meanwhile Stranges are all Cumberbatch thus far. I hope it's a mix as I'm still holding over for a different actor to play some incarnation of Kang. Rumours have it Corey Stoll is returning and playing some version of MODOK, but it'd be great if he could also appear as an AU Kang. The man's a seriously underrated actor and he's got the smug ******* look Kang needs. In Loki's Ep 5 or so we saw Yellowjacket's helmet laying on the ground, so I think he is returning, but I hope it's not just for a retread of his AM1 role. It'll suck if the one character with a slew of AUs and identities, is the one character where we're stuck with a subpar tv actor. I still remember when people thought Richard E. Grant was playing an AU Kang when he was cast in the Loki series...
Either way, they could be testing the waters to see how the Krasinski fancast actually pans out outside of the internet. We'll see. I'm more curious to see if Black Bolt and the Inhumans will reappear. I'd kill to have Fassbender and McAvoy return as MCU Magneto and Xavier, while disregarding the rest of the FoX-Men (maybe Jackman could come back as Old Man Logan and have Keen's Laura be the main Wolverine), but it's unlikely.