Per T124083, some queries — such as prop=links — will accept a revids parameter, but will return results for the current version of the page and not the specific old revision given. This is probably not what most users will expect.
A warning message would be helpful in this situation.
Also consider whether you just want an update to the api-pageset-param-revids message cautioning that many modules operate on the corresponding page rather than the specific revisions listed, or if you're requesting a warning in the API response when this actually occurs. Note a warning in the response that clients can't easily prevent might be considered annoying.
I think doing both would be better than only changing the documentation message. Something similar to the way title normalization is handled would work, perhaps.