FRA - that's annoying, but not unsurprising. It was on-sale yesterday, so it must have been pulled overnight. I was intending to book the first flight, but had a hunch it wouldn't be 02JUN.
I notice KL aren't planning to come back until July, which must set a precedent. With no SN->BRU and no LH->FRA, it's going to be threadbare for connecting flights for a while yet.
U2 still seem to be planning on 18MAY restart, and also not surprisingly, the first couple of weekends flights to sunny destinations are pricing up very high.