He said that in the Comic Pop interview with Sal as well but that's not necessarily true, or at least I suspect Bendis was told the Rebirth creative teams were done after Action #1000. A Twitter user claimed they spoke with one of the creators at NYCC 2 years ago and were told they had 2 more years of stories mapped out.
https://twitter.com/AJGordon2889/sta...38782819258368
Also, Gleason stated in an old Instagram post that they had 100 issues planned for Superman before they were told they were being taken off the title and that Imperius Lex could have ended with Lois finding out she was pregnant with a daughter.
https://imgur.com/hjT4w4M
I remember seeing Tomasi say something similar but I can't find the tweet. In any case, I think it's possible Didio may have pushed the still popular Rebirth teams off both Superman titles to sweeten the deal for Bendis to jump ship from Marvel to DC. Namely by offering him total creative control on one of the DC characters he wanted to write most. If Tomasi and Gleason had stayed on as planned, Bendis would have been less likely to take over Superman entirely and possibly less likely to switch from Marvel to DC exclusive which is what Didio wanted.