Lion is no longer available for sale. No, earlier versions of Mac OS X don't stop working simply because updates are no longer available, or if updates are added. You can always elect not to install updates, if you choose.Will be installing OS X Lion on a HD in a few days. I'm just wondering if the OS X will stop working if future updates are ever added to OS X Lion. Has this been or will it be a problem?
On some 10.7.x releases of Lion it has been a problem. The fix was to remove the PlatformSupport.plist again and it would work again. Some of the updates put it back in place when installed.
When it is turned on after the update, it will say something like "unsupported machine" in white text on a black screen. Only the Mac Mini 1,1 will do this as the Mac Mini 2,1 is fully supported. To fix it, the file is to be deleted. Any changes done to the file will be undone and the file replaced when the combo update is installed. Even if the file already exists, this is how updates work.
That or boot the Mini into Target Disc Mode and remove the file. Target Disk Mode is the easiest and preferred way.