I guess this doesn't affect every site. Mine automatically updated itself as usual. I received the standard email this morning.

Your site has updated to WordPress 4.9.4

Howdy! Your site at [removed] has been updated automatically to WordPress 4.9.4.

No further action is needed on your part. For more on version 4.9.4, see the About WordPress screen

I was definitely on 4.9.3 before this. I'm looking at the notification email for that auto-update right now and remember logging in to confirm it yesterday.

I'm not on a managed WordPress host. It's a VPS with cPanel and I didn't install WordPress using an auto-installer. I installed it manually.