For what it’s worth, anecdotally, it seems the release notes are made available on community roughly 4-6 weeks before the GA release.  

Although, a few times during the Cloud tenure it was right around the GA release.  

The roadmap though is usually made available significantly earlier than that.

The IFS Cloud product release information documents are communicated to customers, partners, and IFS employees at the general availability (GA) date. The documents will be available under the Product Updates menu item here on IFS Community. 

Partners and IFS employees will have access to the documents at the early access (EA) date. This is to allow for testing of the Early Access (EA) release and ensures the quality of the release update, which can change during the EA testing. The documents will be available under the Product Updates menu item here on IFS Community and on IFS Cloud Product Information - Home.

• Early Access date for IFS Cloud 25R1 is April 10, 2025.
• General Availability date for IFS Cloud 25R1 is May 29, 2025.

You always can get a preview of planned functionality for the next release in the IFS Cloud Roadmap, which you can find under the Product Updates menu item. 

Let me know if I can provide other information to help.