I'm really hoping they'll pop up somewhere soon, they definitely have a fanbase eager to see them.
I like the name Legacy for Teddy - other names that have crossed my mind are Exalt, Scion, Caliber, and Claymore. I also think Teddy needs to ditch the green, I understand as part skrull it makes sense, but its not even his default form/color. Every time he's knocked out he reverts to his human form and with the changes that have happened to Chulk/Brawn he's been further edged out. Perhaps let him make more creative use of his shape changing for strength, agility, or even different sword forms with spacesword.
Arcane is definitely perfect for Billy, but I don't think he's in need of a name change as much as Hulkling. While there are definitely problems with Wiccan, its readily identifiable if anything.