Currently, the standings are:
Mets: 89-72, clinched wild card spot
AZ Diamondbacks: 89-73
Braves: 88-73

So, if the Mets win game 2, then AZ gets the last wild card spot because they'll be at 89-73 and the Braves will be at 88-74.

If the Braves win game 2, both Atl and AZ will be at 89-73, and the Braves will get the final wild card spot because they have the tiebreaker over AZ.

(I don't know if the Braves win if they get #5 and drop the Mets down to #6 in the seedings, or if the Braves would be #6.)