FreeBSD is a Unix-like operating system that has roots in Berkeley Software Distribution (BSD), which itself originated from research conducted at the University of California, Berkeley, in the 1970s.
The OS is known for its advanced networking features, security capabilities, and freedom-focused licensing, finding use in a wide range of hardware ranging from embedded systems to being the backbone of major cloud services.
Unfortunately, it looks like KDE’s Plasma Login Manager won’t be working on it, as an accepted merge request sees the focus turn to compatibility on Linux systems.
You can keep using sddm. It isn’t being discontinued. In fact you can use any login manager you want. Plasma is not going to enforce one.
I personally am happy about the new plasma login manager, because it will allow features they couldn’t reasonably implement with sddm.
The people upset about this is a classic case of getting upset about things that won’t affect them at all.