I don't know what a tubeless blowout sounds like, but this might have been the rim tape failing and the pressure blowing a hole in the tape at a spoke hole. In which case the tire didn't fail, the rim tape did.

I'd check the old rim and see if there's a hole in the rim tape has a hole in it at the spoke hole.

I realize we're talking fat tires and low pressure, but it's an easy check to try to understand what happened.

If there is a hole in the rim tape (blown out by air, not poked in by a spoke), then the solution is stronger rim tape or 2 layers of rim tape.

BTW the max pressure spec printed on the tire is half the tested blow off pressure.