This area hasn't been underwater in a meaningful way since the 1927 flood of the Mississippi.
Any situation that floods that area is going to be well beyond 100-year floods, likely beyond 1000-year, and (like the 1927 flood) predicated on catastrophic levee failures that result in the Mississippi being over 100 miles wide.
Is it possible? Of course. Is it likely? No. Would there be much bigger issues than a server farm being offline? Yes.
The worst-case scenario from a storm that hits locally (which, e.g., the 1927 flood was absolutely not a consequence of - it was water from upstream, which climate change will weaken because of decreased snowmelt) is like Harvey over Houston (similar terrain). But this is much farther inland and could not replenish itself from the Gulf.
That said, it is in the middle of nowhere.
This means it isn't securities fraud when Meta tries to meet "climate commitments" due to the greenwashing of fossil gas generation by the state of Louisiana. Louisiana is a low regulation jurisdiction that doesn't care if most of the state ends up a Superfund site, so it is ideal to colocate data centers that are going to burn up a bunch of fossil gas there over their lifetime (when they are unwelcome elsewhere).
https://en.wikipedia.org/wiki/Cancer_Alley
https://www.propublica.org/article/toxmap-poison-in-the-air
https://www.propublica.org/article/cancer-alley-louisiana-ep...
https://www.propublica.org/article/welcome-to-cancer-alley-w...
"World Bank is urging energy firms to gather the gas and sell it to businesses and consumers.... Companies can use the gas in mobile electricity generating stations, to power their oil drilling sites, or as a fuel in petrochemical plants."
https://www.bbc.com/news/science-environment-63051458
https://www.worldbank.org/en/programs/gasflaringreduction/ga...
https://www.reddit.com/r/explainlikeimfive/comments/cvawx7/e...
It’s north of the Old River/Morganza flood control system. I think this would have to fail first in order for the Meta site to be in danger.
Also, if the New Madrid fault went off again, I think you’d kiss this site goodbye. But if that happened you’d have about a million higher priority concerns than a stupid data center.