As WSUS was included in Server 2025, WSUS will work in a supported state until at LEAST 2035, so you have at least 10 years of use. There is no need to rush out to find a new system. If the current system works for you, keep using it. WSUS is embeded into MANY systems - from 3rd party tools to even Microsoft tools (ConfigMgr uses WSUS under the hood).
Microsoft also has not given us clear details as to if Drivers will be able to be manually imported into WSUS using our Import-WsusUpdate or Microsoft's "script" which is very inferior to ours.
Microsoft's notification is literally just saying they are 'stopping' all development on WSUS. Some may say that development was stopped a long time ago, but now they are making it official. I say that there has been development for WSUS, but it was all back-end to support upgrades of Windows 10 and 11, UUP, etc.