Now that hardware terminals are gone, it's a very safe bet.

But xterm is,way rich, it supports esoteric advanced stuff like sixels, etc. For a basic text editor, without split windows, colors, and such, a subset of VT-52 capabilities may suffice.

My guess would be it targets VT-100, but it wouldn't have to be hardcoded, non-curses applications can still make use of the terminfo database to determine the capabilities of whatever terminal they are attached to.