I'm not sure there's fire suppression effective enough for this type of leak (especially given rocket constraints)
Actually the Super Heavy (first stage) already uses heavy CO2 based fire suppression. Hopefully not that necessary in the long term, but should make it possible to get on with the testing in the short term.
It might not even be about fire suppression. Oxygen and different gases can pool oddly in different types of gravity. If oxygen was leaking, it may be as simple as making sure a vacuum de-gases a chamber before going full throttle.
We know nothing, but the test having good data on what went wrong is a great starting point.
Replying to this comment so people can see the incredible video of the breakup taken from a diverting aircraft:
https://www.reddit.com/r/aviation/comments/1i34dki/starship_...
If you can displace the oxidizer/air remaining in the volume why not.
just increased venting to keep any vapor concentrations of fuel and oxidiser below that capable of igniting, even simple baffling could suffice as the leaks may be trasitory and flowing out of blowoff valves, so possibly a known risk. Space x is also forgoeing much of the full system vibriatory tests, done on traditiinal 1 shot launches, and failure in presurised systems due to unknown resonance is common. Big question is did it just blow up, or did the automated abort, take it out, likely the latter or there would be a hold on the next launch.
Aerospace fire suppression is generally Halon, which would purge the cavity with inert gas.