Dick yes, he's long since proven that he's worthy of being counted among the best of the best. He's arguably already counted as such, depending on who you ask.
Same goes for many of the Lanterns, most are equally capable and deserving of such lofty titles. But unless the Lantern in question is Kyle Rayner returning to earth to pick up his old Marz era Everyman archetype, I'm perfectly fine with the Lanterns largely staying off world, they're more fun as space cops than jewelry-based superheroes.
Donna.....not so much, I don't think. She's powerful, experienced, and capable yes. She'd certainly be able to keep up in a team of next-generation GOATS, but I don't think she'd be much of a stand out member and would largely end up in the background, and she comes with a whole lot of baggage and broken history. I imagine that Yara would find her way onto a hypothetical post-League roster instead; Donna seems to be a character few writers want to deal with while Yara was an instant hit (even if her sales didn't hold very long).
I'm hoping that if we do end up with a League replacement team, that it's not just the Future State roster or even a Big 7 legacy group, but brings in the characters who feel like they could realistically step into the League's boots, and not feel like a gimmick group. We'd obviously get a good amount of legacies, since many of DC's best and brightest are legacies (Dick, Kara, Wally, etc) but I don't want or need a complete Big 7 copy. Get Mr. Terrific, Blue Beetle, Cyborg, heroes like that into the mix, and not just Superman Jr., Batman Jr., Wonder Woman Jr., etc.