Okay, so if we go over all the possibilities, let's first look at who is a member in the comics and what their status is for the MCU:
- Iron Lad (Nathaniel Richards): We have seen a child Nathaniel Richards variant who would become Victor Timely in Loki (portrayed by Nasri Thompson), but no indication that Iron Lad is ever coming.
- Patriot (Eli Bradley): We have seen Eli in tFatWS (portrayed by Elijah Richardson), but no indication of powers yet
- Hulkling (Dorrek VIII/Teddy Altman): No real indication that he will show up anywhere yet, though there have been scoopers who claimed he has already appeared somewhere.
- Wiccan (Billy Kaplan): We have seen a young Billy Maximoff as both a magical construct (WandaVision) and alternate universe version (MoM) portrayed by Julian Hilliard. Everything is pointing to a fully formed Billy Kaplan with presumed magical abilities appearing in the Agatha show (portrayed by Joe Locke)
- Hawkeye (Kate Bishop): Has already been a main character in Hawkeye and is pretty much confirmed for the Young Avengers (portrayed by Haley Steinfeld).
- Stature (Cassie Lang): Has already appeared in the Ant-Man franchise and as of Quantumania has her powers (portrayed by Kathryn Newton)
- Vision (Jonas): No indication that he will show up anywhere.
- Speed (Tommy Shepherd): We have seen a young Tommy Maximoff as both a magical construct (WandaVision) and alternate universe version (MoM) portrayed by Jett Klyne. So far no indication that Tommy Shepherd will show up anywhere, but the existence of Tommy Kaplan indicates Tommy likely does exist as well somewhere.
- Miss America (America Chavez): America has been a major character in Multiverse of Madness (portrayed by Xochitl Gomez).
- Kid Loki (Loki Laufeysson): A version of kid Loki has appeared in Loki season 1 and currently exists within the Void (portrayed by Jack Veal). There has been no indication that kid Loki will leave the Void so far.
- Marvel Boy (Noh-Varr): No indication that he will show up anywhere.
- Prodigy (David Alleyne): No indication that he will show up anywhwere
I think the ones in green are pretty much given since they'll all have been firmly established and had a major role in a movie or show beforehand. I think the team really needs Teddy though, and I hope they don't just cut him out or replace him with someone like Skaar.
Then there's some other candidates in the MCU who weren't on the team in the comics:
- Ms. Marvel (Kamala Khan): Has had her own show and appeared in a movie. Basically confirmed for Young Avengers
- Ironheart (Riri Williams): Has had an appearance in a movie and will get her own show. No indication for future teamups
- Skaar: Has had one minor appearance in a show. No indication for any future plans.
- Love: Has had one minor appearance in a movie. No indication for any future plans.
I think Love is the least likely out of these. She's not a beloved character from the comics (as far as we know) and the actress is far younger than any of the others. I'm personally not a fan of having Skaar on either, since this isn't the type of story I'd like to see Skaar in and I would hate for Teddy to be replaced. Riri is possible, since she was also on the Champions team of young heroes with Kamala in the comics. In my mind she felt a bit too old, but I guess she isn't actually any older than Kate.
The ages do feel a bit odd regardless to me. The age difference between Xochitl Gomez and Haley Steinfeld is a full decade. And while we don't know exactly how old America Chavez is in-universe, there is at least a difference of 7 years between Kamala Khan and Kate Bishop. So we'll have characters still in high school together with characters who will statistically graduate college soon.
I don't think they'll have Miles Morales involved, because he's not been set up yet and the Sony deal might complicate things for him.
If I had to make a Young Avengers project right now with the current state of the MCU, the line-up would probably be
- Kate Bishop
- Kamala Khan
- Cassie Lang
- Billy Kaplan
- America Chavez
- Teddy Altman (find a way to introduce him)