Pratt came up with their own adaptive XA101, in case. But primarily has been pushing a Engine Core Upgrade (nee Engine Enhancement) plan and new Emergency Power and Cooling System, which is now locked in, which leaves most of the existing F135 engine intact. It too claims double the cooling capability, with 7% range & thrust boost. https://www.defensenews.com/air/2023/03/13/pentagon-rethinks... https://aviationweek.com/defense-space/aircraft-propulsion/c...
Personally for a plane the US alone expects to purchase well over 2000 of, with ~$80m a plane expected & many significant computer, electronics warfare, & sensor upgrades coming in Block 4 / Technology Refresh-3 (potentially raising price) (https://www.thedrive.com/the-war-zone/new-electronic-warfare...) ... I do wonder if maybe having another really great engine upgrade isn't advantage enough. Hopefully the new Pratt & Whitney is at least good enough. Also noted, the Air Forces Next-Gen Air-Domination (NGAD) might well use adaptive-engine tech.
Notably though, this article is about a defense of the ECU path, which hopefully is indeed sufficient. Also nice, we have many allies who have purchased these planes, and they'll be able to keep a sizable fraction of their existing engines during this upgrade as well.