This just looks like releasing the update before it was ready. The new widget is available and can still appear if you don't try to customize it (EDIT: I realized I only had 5 actions chosen instead of 6. Once I added another action, I could add the widget). At least that works on my phone. If I try to customize it, then the 'Done' button does nothing. There are all sorts of things wrong with it, including placement (cannot center it on my phone which is a not-at-all-rare Pixel 3a) and the dark color option is gone.
I doubt that widget functionality was entirely 'removed' on purpose, they just had a poor v10 launch and did not test it properly. It would be great to see an official response from a staff member on here, because many of us woke up today with their widget disappearing and are probably more irritated than I am.
(though that will change if Evernote doesn't sort this out in a couple weeks)