As far as I know, most are still operational. I still have most of my computers purchased and used along the way. I have been an avid supporter of Apple products since 1983. Maybe if I purchased the program from them with confidence it would work smoothly, an in an 'Apple' kind of way, not a 'PC-pray it'll work kind of way' then I would feel better about this situation. One is 'TuneF*b' (I altered it as to not promote it). There are programs which can be purchased which supposed allow the devices to continue to be used. There are not millions of these devices out there being used any longer, however I bought into them and had been using them as the place that signs my paychecks does not allow us to use newer devices with Bluetooth for our music (earphones allowed/music allowed as the environment is bordering on OSHA decibel violation). I understand that the move is a financial based one. I believe Apple no longer supports the older devices.
How about a nice article that clearly talks about the lack of support from the latest OS to recognize and allow one to smoothly continue using the no longer supported models such as the iPod Classic.