Hi Ashizian!
All the content I make for Minifantasy is community driven. All of it is suggested and voted by the Minifantasy Patreon community members. This includes all new Itch asset pack releases and also all the Patreon-exclusive sprites.
So, answering your question, as I don't have a personal road map for what is coming in the near future, I can't tell what exactly I will be releasing in the following months. I will work on whatever the community suggests and votes.
However, we already have in the collection
+ An asset pack with snow (https://krishna-palacio.itch.io/minifantasy-icy-wilderness)
+ Some birch trees with autumn foliage in this pack (https://krishna-palacio.itch.io/minifantasy-crafting-and-professions-i) including variations of it on Patreon (https://www.patreon.com/posts/exclusive-more-65205125)
+ A summer/beach Patreon exclusive (https://www.patreon.com/posts/minifantasy-67928821)
+ Different grass types that could be used on the ground to represent the changes on it through the seasons.
With a little bit of editing + mixing and matching different assets already present in the collection, I believe it's possible to have seasons.