Tomorrow - *Asset Mods will also become available for Cities: Skylines II. The free beta update to the Editor will allow modders to implement their own unique props and buildings, and share them with the Cities community through the Paradox Mods library.

This is the last thing on our Road Map for 2025, we will have a Developer Diary from Colossal Order about the Asset Modding tomorrow, so keep an eye out for that!*

from the Supply Chains & Skyscrapers launch article.