Right, they can't ..nor can they prevent NFL players from being used in a simulation game. The NFL can only stop a company, not named EA, from using NFL teams, stadiums, logos, etc in a "simulation" style game. That's it.
That being said....
Retro Bowl, a mobile game, features 11-on-11 football with with AFC and NFC conferences, each with four 4-team divisions (East, North, South and West) using actual NFL cities with the same alignments as the NFL. It also has the NFL team uniform color schemes.
However, it does not have actual NFL team names, stadiums, logos. It also has generic rosters though you can customize everything...rosters, team names, unis, etc.
It has a 17 week, 16-game schedule with a 12-team playoff that mirrors NFL seeding and tie-breaker rules. And then of course there is a championship game, the Retro Bowl, pitting the AFC and NFC Champs against each other.
Granted, this is a mobile game fashioned after the classic Tecmo Super Bowl. Qtrs are max 3 mins long, offensive plays are randomly selected. There are no penalties. Defensive possessions are text simulated. But...it is 11-on-11 football with regular rules.
Off the field, there's salary CAP, free agency and a draft. You also hire assistant coaches, deal with injuries, level up player abilities, manage stadium, training and rehab facility upgrades, monitor team morale and conditioning.
Also, player game, season and career stats are tracked along with any awards they win. Record books are kept and you can even induct players into a Hall of Fame.
Maybe it is because Retro Bowl is just a fun mobile game by an indie developer that they've managed to avoid the legal wrath of the NFL and EA....
Or ...it could be an actual example of where the lines are drawn within that EA/NFL "simulation" exclusivity deal and be a small preview of how much room 2k actually has to work with.
I guess we will just have to wait and see.