I see from another post that we're talking about EWR-CDG in the summer.

If you just got the schedule change notification from AF, it's also not impossible that VS won't know about the schedule change for some time (e.g. the advice in the Delta forum is to wait a couple of weeks for DL's systems to see the schedule change), and thus won't be able to do anything.

If there's VS availability on a morning AF LHR-CDG flight, JFK-LHR-CDG (on VS, most likely) is probably a reasonable thing to look for. If you can get to BOS (might have to do it on your own dime: there's now the possibility to transfer airside whether flying DL or AA/UA/WN/B6), there are likely at least 2 DL or AF flights to CDG which will arrive closer to your original arrival time).