That is the main reason I've always been pessimistic about more Classic teams being included. Bargaining with individuals who have the right to ask for anything they want (Or like Charles Barkley and Reggie Miller just not wanting to be included) makes that process pretty hard. I'm all for them but I always practice a "Glass half empty" mentality with them..Enjoy them while I can..
To the person who asked would I pay for them as DLC the answer is yes. Having an option to download 1 or 2 teams in a pack for an additional 5 bucks isn't much damage and may help them earn cash to go out and spend for more legends.... I did the same thing in injustice to use batgirl, lobo, etc.