Jon is their way to soft reboot Superman like they’ve wanted to do. No marriage. No set love interest to limit him. No pre conceived notion of how he “should” act or how he should operate. Jon has been a teen almost as long as he was a kid, soon he’ll have been a teen longer than he was a kid. DC doesn’t care about kid Jon fans, they’ll toss them a bone with Tomasi’s series but they’re not interested in keeping him there anymore clearly. I don’t know how to feel about it honestly.
I checked his Twitter, unless he deleted it all he’s confirmed is that Action is building towards a Superman event with Janin, nothing about giving up either books. But to be fair if that was happening it’s way too early to be confirming that considering Sept 2021 seems to be when the big Superman event that’s going to shake things up will happen.