I think this should be considered to enable. It is a basic important OS graphics feature. Wayland is default these days for most desktop environments. Lxqt with wayland and labwc compositor would benefit from this streamlined configuration. I think many dietpi users may use graphical environments and benefit from dietpi’s setup optimizations that Raspberry Pi OS currently doesn’t provide.
raspi-config utility enables wayland and labwc compositor in Advanced options but I don’t know if this utility may conflict with dietpi-tools or be migrated. Probably the best place to enable would be on dietpi-tools display settings.
On the other hand IMHO Xorg should be deprecated and save a lot of packages for a desktop install.