Just having a think about how @UEFA are going to fit in the Play Offs into the current FIFA calendar. As it stands these are the current international dates before the Euro 2020 tournament (in June 2021)

Sep - 2 NL games
Oct - 2 NL games
Nov - 2 NL games
Mar - 2 WCQ games 1)

So unless UEFA/FIFA create new international windows either 2 NL games or 2 WCQs will need to be rearranged.

UEFA have already confirmed the 2 WCQs & NL finals originally scheduled for June will also be rescheduled. This will also cause a problem. 2)

The original plan for WCQs were:

Mar 21 - 2 WCQs
Jun 21 - 2 WCQs (already postponed)
Sep 21 - 2 WCQs
Oct 21 - 2 WCQs
Nov 21 - 2 WCQs
Mar 22 - 2 WC play offs 3)

If UEFA want to continue with the Nations League they will have 4 games (2 play offs plus 2 WCQs) to fit in for the 16 teams, the NL final for 4 teams and 2 WCQs for everyone else. 4)

Could they play the NL games, as planned this year, the Play Offs in March 2021 & start the WCQs in Sep 2021? Yes but they will still need to create new international dates to fit them all in. 5)

The 2022 FIFA calendar has already changed due to the winter WC. As it stands this is the schedule:

Mar 22 - 2 WC play offs + friendlies for everyone else
June 22 - 4 NL games
Sep 22 - 2 NL games
Nov/Dec - Qatar WC

There is no October international date in 2022. 6)

Some people have suggested playing 3 games per international window to catch up. Currently FIFA regulations don't allow that but that could be changed if FIFA change their regulations. 7)

I can see only 4 options:

1. Cancel the NL (unlikely)
2. Create new international dates
3. 3 games in some of the international windows (unlikely)
4. Push everything forward a year. No internationals in 2020 and the Qatar WC is played in 2023 and then the next WC in 2027. 8)

Sadly I think option 4 is the most likely End