200 Level warnings in revalidation

The spec says that all 200 level warnings must be retained after a successful
revalidation.

However, it also says that all end-to-end headers (Warnings are end-to-end)
must be replaced after by the corresponding end-to-end header in a revalidation.

So if we had a cached copy of an entity that has a 200 level warning associated
with it and when we revalidate, we get a Warning header w/o the 200 level
warning, are we supposed to keep it or not?

Thanks,
Chris