But I thought DeX was the "use your phone like a PC" external peripheral support, which is staying, and link to Windows was always just another thing? Are they just removing duplicated functionality?
This is incredibly misleading, and not because of the author for once.
Samsung apparently has a "DeX for PC" app which essentially mirrors the phone screen to the PC. DeX, the desktop mode for when you cast or plug your phone into a display, is not going away. DeX for PC has been replaced with the same functionality in Link to PC (previously phone link), and Samsung is choosing not to continue making a competing product with their partner (where I believe Samsung is still the only one that supports screen mirroring in Link to PC anyway)