I am finally beginning to understand what the concern is - that some contaminated floodwater soaked into the corks (while it was temporarily submerged) and that floodwater will work its way through the cork into the wine, like a heat-seeking missile relentlessly chasing its target.
But the physics don't work, do they? The pressure exerted by the floodwater pushed the floodwater into the cork while submerged, but once the greater pressure of being underwater was removed, then the path of least resistance would be back out of the cork into the atmosphere, rather than deeper into the cork, which would be far denser than the atmospheric pressure. So, the contaminated floodwater would evaporate back out the top of the cork, where it came in, leaving behind (potentially) some dried up contamination/bacteria at or near the outer portion of the cork.
If that is the scenario we are all imagining, then I think re-corking is unnecessary (although not necessarily pointless), unless you expect the bottles to get wet/flooded periodically to where the bacteria may have the opportunity to get deeper into the cork, especially if you plan on aging this wine for 20 years. Otherwise, forget about it and drink it when you're ready. Uncorking and re-corking exposes the wine to more bacteria and other contaminants as well as oxidation, with certainty, than the potential of contamination from being underwater for a short time, possibly, but probably not, contaminating it.
At most, I would uncork the bottle you believe to be the most likely to be contaminated and look to see how far the cork is discolored, and go from there. Until you look at it, everything else is just speculation and theory.