Personally I don't really see the merit of continuing to develop the MATE DE. I feel like Xfce does the lightweight DE better while also not being too far away from working entirely under Wayland.
And for those who just want an easy to use 'standard' windows-like DE, Cinnamon seems like a better option than MATE, as it's more actively developed and also moving toward Wayland support.
unless there's something I'm missing, MATE just feels like a needless duplication of effort.