The 2020 US NEC seems to have provisions for an EPO, but I'm not sure when it was added if it was present during the time of OP's incident:

* https://www.f-t.com/post/emergency-power-off-in-data-centers

EPO disconnects for generators was around earlier than the above:

* https://www.mgiepss.com/blog/emergency-power-off-epo

You'd generally not want to have the sprinklers go off while things were energized, but there could be a mechanism to monitor flow, and only cut power if sprinklers were actually sending out water. But even if this was present, your first priority would be for the sprinklers to not go off as there would be a lot of clean-up / drying needed after the fact.

Unless you have a mist system (NFPA 750), sprinklers put out a lot of water.