I don't think anyone (the teams, MLB, the network) wants to lose the off day. Lots of tweets already suggesting they start Thor/bullpen game today. They could also go with Falter/bullpen initially and let Wheeler make the start after any delay. But it's not like it wouldn't be the same issue for the Braves.
Of course if Wheeler and Wright both start and then are unable to return they theoretically become available for a few innings in a Game 5 (and probably would be regardless).
A drawn-out game probably gets us that Nelson or Gibson appearance we don't want.