WSUS is now deprecated
Not really surprising - there hasn't been any meaningful updates to WSUS for a very long time... there are improvements that could be made - but no appetite to make them.... i imagine because the cloud solutions have a direct cost (and are therefore revenue producing) whereas WSUS does not.
The argument could be made that the ability to patch en-mass via products such as WSUS (and by extension, SCCM) is part of what you are paying for when you pay for a Windows license... the same as the the idea that you're paying for supported product... its all part of the eco-system.... and without support, or patching or sysinternals tools or <insert other tools here> the Windows eco-system becomes much less attractive.
Anyhoo - obviously not the way the MS management see things.... it appears as if anything that doesn't have a direct revenue stream associated with it is being killed off. Not surprising - but it also really sucks being shoe-horned into a immature platform that doesn't always fit business or technical needs.