I'm booked this summer on a JFK-LHR-TLV itinerary (all on VS but booked with DL and booked onto DL flight numbers).

I just got an email from DL telling me that my flight times have changed, leaving me with exactly a 1:00 connection time at Heathrow. DL said that connection time may be insufficient and suggested I contact them to find an alternate itinerary.

Looking at the VS website, it seems 1 hour is the minimum connection time they suggest for same-terminal connections. I assume my arrival and departure would be in the same terminal, but please correct me if that's not the case.

The fact that DL hasn't automatically rebooked me suggests this is still a legal connection - is that correct?

I guess I'll see if they'll put me on their own nonstop, but I wanted to ask how impossible (or not) this connection would be first.