If there's more than 1, I'll also state the number of months with varying holidays, I'll also include which ones are up in the air for replacement regardless.

Pizzeria: 2 (April) I'd say May and August could also have been replaced.

Burgeria: 0 The only one to lack any holiday lineup, I've seen varying lists of ideas. Ideally, it should share as few holidays with Cluckeria as possible since a lot of the ingredients would overlap.

Taco Mia: 2 (August and May) I'd say Day of the Dead should replace Halloween, also I can see Holi in March.

Freezeria: 1 Although we most likely won't see another lineup, I think August, September, and May could be replaced.

Pancakeria: 2 (August, September, and April) Can't say I see any other months having new holidays.

Wingeria: 1 I'd say swap out August or September, as well as October since I can really see Day of the Dead being in Wingeria Deluxe.

Hot Doggeria: 2 (May, August, and September) I could kinda see Day of the Dead replacing Halloween, but not as much as Taco Mia or Wingeria.

Cupcakeria: 3 (May, August, and September) I can also see Volcano Gala returning since Willow hates Summer Luau.

Pastaria: 2 (January and February) The only other month I can see up for grabs is March, since I can't see any of the currently Pastaria-exclusive holidays being replaced.

Donuteria: 2 (February and May) Can't say I see any other months being swapped.

Cheeseria: 2 (September and March) Can't see any others being swapped, except maybe February.

Bakeria: 2 (May and August) I can for sure say that Bakeria To Go 100% should've had Holi instead of St. Paddy's Day, since SPD has 2 flat placeable toppings while all others have 1 flat and 1 non-flat.

Sushiria: 2 (August and September) Only other one I can see replaced is February, since for May I can't see BTC or OF in Sushiria, and CBF and CC are in other months. Also I can't see LNY and LLM being in a game together.

Scooperia: 2 (April and May) I completely don't understand why May varied, the game's set in OnionTown, OnionFest should've been in all versions, I think September was more up in the air.

Mocharia: 1 I'd say only April and May could be swapped out.

Cluckeria: 1 I'd go with August, plus April maybe?

Paleteria: 1 I'd say August and October.