I have been studying and testing with cemu's new online capability. and i say its pretty good.
Indeed can you play with other wii u owners but it is also possible to play with other cemu players as well,
As for super smash bros wii u without dumping mii data you will have a unknown Japanese name instead of your name and you will have a white square in mii box instead of your Mii, also if you were to try to use a mii character it would not show the mii's head.
real wii U owners will see...
My Findings on CEMU's new online update
Indeed can you play with other wii u owners but it is also possible to play with other cemu players as well,
As for super smash bros wii u without dumping mii data you will have a unknown Japanese name instead of your name and you will have a white square in mii box instead of your Mii, also if you were to try to use a mii character it would not show the mii's head.
real wii U owners will see...
My Findings on CEMU's new online update