I know two classic settings are certain, but do we know we're getting them in 2022? I thought it was just in the next two or three years? (2021-23).
If we are getting 2 classics, 2 new, 1 revisit, and 1-2 Magic settings, that's 6-7 settings within the next two years. If we assume only 1 Magic setting, that's still 6, or three per year. I would think they would spread them out, so we'd see something like:
2022: classic, new, revisit (which is classic)
2023: classic, new, Magic
Or something like that.
As I said to Parmandur, I think a Manual of the Planes book could fill a splat slot, either in 2022 or 23. And I highly doubt we'll see more than 3 settings in 2022.