LX has been flying to EWR for years...

But to the OP, I agree that for the next few weeks, both LX and LH seem to have arrived at a stable, very minimal emergency flight schedule that includes a few transatlantic flights. These should operate normally unless governments change the rules again.

However, as per Unterwegs, make sure you have the paperwork required to continue from either FRA or ZRH to your destination. Intra-European borders are closed to non-essential travel.