Ath96:
This is a classic bird-in-the-hand vs. two-in-the-bush case. It sounds like UCLA Anderson is a great fit for you, so why give it up? Reapplying to other schools can be successful, but the problem will be that you likely have to wait until R2 of this coming season as it's very hard to demonstrate a considerable change from R2 of Year 1 to R1 of Year 2. Without major improvements in your profile (assuming you have none), I am not sure what the argument would be to the M7 and comparables as to why you are a better candidate. If you have new feathers in your gap (GMAT/GRE score, promotion/change of job, etc.) then it's worth discussing.
FWIW, I don't think a deferral is an option (schools have been much stricter) about granting them post-pandemic.
In any event, without knowing a ton of information about how you applied and any feedback you might have gathered, I say take the offer and enjoy your 2 years. Anderson is a fantastic program!