I use xfce, but I don't seem to have these key mappings. They don't do anything for me.
Oh .. xfce works like popular tiling windows manager - i3 or sway .. you can map your keys in the settings but out of the box super + left arrow is to align the window on left half of the screen .. and super+ right arrow for alinging on the right side .. you can check your jeyboard maps in Settings > windows manager > keyboard ... and edit the shortcuts there .. Its kinda same in gnome and cinnamon too .. bit here and there