They say they'll still update software and maintain support, but they're done manufacturing, and stock is limited to whatever stores currently have.
www.theverge.com
Here's Logitech's own announcement.
I, for one, still love my Harmony 650, and I hope it has a long life now that it's irreplaceable.

Logitech officially discontinues its Harmony remotes
The CEO told The Verge in 2019 that the remotes were a small part of its business

Here's Logitech's own announcement.
I, for one, still love my Harmony 650, and I hope it has a long life now that it's irreplaceable.