Interesting development.
There are 2 ways this could go:
1. They are losing the license. Usually when you negotiate an exit its not immediate. You complete the current project and then go your separate ways. This works best for both sides as for the license owner you wouldn't have enough time to find a new licensee and have them work on making a release, and the license holder wouldn't be caught in a really bad spot by having to throw away months of work. By instead releasing an expansion the team wouldn't have to devote as much to a full game that would ultimately be wasted investments, and it reduces the odds that Motorsports releases another dud that would harm the brand. A month or two from now it could be announced that the license is going somewhere else but the expansion to 21 would still be released.
2. They are keeping the license and genuinely believe this is the path to right the ship and Nascar has signed off on it. According to this plan, they are doing what many gamers want Madden to do to fix its issues.
Initial thoughts are that scenario 1 seems much more likely, but I can't rule out scenario 2

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