I think these rumors are just that.
Ford hit a nice balance on the timberline, just need to offer it in a Max version also and a bit more of the Raptor tech, like locking diffs instead of clutch based, maybe a bit off the SEMA truck. It comes with the same raptor engine and tuning already, I highly doubt ford drops a HO V8 into these.
Unless it's used to increase towing capacity or fuel economy, I don't see any engine changes coming in the next version for 2025.
Perhaps the Navigator might get a higher output Hybrid system or V8 to compete with the Escalade-V.
I'm not seeing either market share or competition for Ford to build a Raptor R like 8 passenger off-road full-size body on frame SUV.