I'm having a little trouble with this explanation…
To have combustion…you need fuel, O2 and a spark.
It must have been a hell of a leak that proved to be beyond the cavities venting capacity and compromised structural integrity causing it to break up….
And if it was just an O2 leak (no combustion) why add fire suppression in the future?
Don't know…something just seems off with this explanation…
Why did SpaceX's Mission Fail?
SpaceX CEO Elon Musk shared early information on the cause of the explosion on social media.
He explained that the rocket broke apart because of an oxygen/fuel leak in the cavity above the ship's engine firewall. This leak created pressure that proved to be beyond the engine's vending capacity.
Musk said, "We will add fire suppression to that volume and probably increase vent area, in addition to obviously double-checking for leaks." There is no sign that the next launch will be postponed past next month, he said, expressing optimism about upcoming launches.
https://www.msn.com/en-in/technology/space-exploration/spacex-starship-mission-faces-major-failure-elon-musk-explains-why/ar-AA1xmKuB