I think the general consensus is that this year's acts have been offered the same spot for next year and most will take it. The big issues look to be at the top of the Pyramid with the fella Ken, who tends to have solid info about European festivals, saying that neither Kendrick or Swifty have made plans to reschedule as yet. Macca is looking a bit more positive (couple of clues point to it, he mentioned 'postponing' his Glastonbury appearance on the Howard Stern show - rather than outright cancelling - and his daughter made a social media post about him coming back next year).
Sub wise; Lana Del Rey looks like she's not around next summer and there was some info the Noel G was also planning a year off from touring (although that might be this year now!), and we never worked out who the third sub was for this year so all 6 places are still up in the air. So we could be in a position where the vast majority of the card rolls over but from a first poster POV it looks very different (across those top two rows).