If it happened it wasn't intentional but two years ago they said the "minimum recommended system requirement" was windows 7 and apparently as of a couple days ago it changed to "the minimum system requirement" in the knowledge base. Check the other support threads someone hosted the files that need to be downloaded apparently at this point you can still play the game with OS as old as XP (and I assume vista) but the launcher no longer works. this thread is the one someone posted a patch but up to you if you use it since as the poster says himself. https://forums.daybreakgames.com/eq/index.php?threads/kernel32-dll.239855/page-7 Post is near the bottom of the thread as of this message.
Yes, Vista is a dead OS: https://support.microsoft.com/en-us/help/22882/windows-vista-end-of-support You shouldn't use a video game as your indication of whether an OS is dead or not...
Downloading the changed files, copying them to your EQ folder, and running -patchme works on both XP and Vista.
I have 64 Bit Vista Premium on one computer, but I still have to bypass Launchpad to log in on that computer since the last patch.