do no worse than 1 game worse than the Mets at the Brewers (a potential WC preview series), and the two games on Monday will still matter for determining the NL WC teams.
The Mets can get swept and the two games on Monday would still matter for determining the WC teams. They cannot be eliminated over the next 3 games.
The D'backs can be eliminated if they pick up 2 more losses than the Braves do over the next 3 games. That would require either the Braves to sweep KC or the D'backs to be swept by SD.
All 3 teams still control their own destiny. If the D'backs win out, they are in. It would potentially force the Monday double header and one of the Mets/Braves would be guaranteed to finish with more losses than the D'backs if they didn't already.