The truth is if the Phillies re-sign a healthy and expensive Wheeler, well, they can still afford it. But it might also mean something went wrong (either losing Nola, Walker or Ranger being disappointing, or the younger pitchers not working out as well as hoped). Locking up the younger homegrown player who they also need in 2024 is a no-brainer and shouldn't be connected to Wheeler scenarios in any way. Nola and everyone else (and Wheeler's performance) will set that path.
I don't think they want to do this one quietly. There will be a celebratory press conference in Clearwater. This is going to be the Ryan Howard deal except with a higher-value/more highly skilled player who is actually a free agent, and with less risk of rapid decline (if not no risk). Maybe not an overpay, but fair market. Even when Howard signed that deal coming off a great season he was nowhere near the player he was in '06 and '07; he put up 3.8 WAR in a very good 2009 but Nola just put up 6.0. I think that Athletic story actually understates how good he's been, even with the occasional struggles (two strikes or late innings/late season).