Yes, Eccleston apparently had a big falling out with Russell T Davies. No idea on the details, but a few people I know who work on Doctor Who crews said it made him continuing on in the role pretty much untenable.

Like you, I was beyond thrilled when Doctor Who returned. I'd dreamed about that happening for years, but didn't ever expect it to really happen. So gutted about the Whittaker/Chibnall glitch though. Actually let's just say Chibnall glitch as I consider Whittaker a fine actress who did her best with extremely poor material.

I should add for the woke-a-cola brigade claiming Doctor Who has always had social commentary that yes it has. The difference is, it wasn't preachy and joyless, but inherent in the material without bashing the viewer over the head.