It seems that they are giving them plenty of warning and an entire final season to work with.
Today's email from TVline says that the CW suggested to all concerned (all the ones on the bubble) that they craft a season ender that could also be a series ender. Legends of Tomorrow seemed to do that.
Speaking of housecleaning at The CW, per TVLine: "Riverdale to End With Season 7 at CW, to Premiere in 2023"
The rampant housecleaning at The CW makes me wonder what's going to be left to put on the air next season.
The other day The CW released a full schedule. They are cutting back to, I think, four days of original programming.
While we're all reflecting on This Is Us and how well it sticked the landing in its series finale, here's a look at how New Amsterdam wrapped the current season, per Pajiba: "The 'New Amsterdam' Season Finale Was a Bleak, Chaotic Mess"