The legacy of the MissingNo glitch carries on in a different way.
However, the old MissingNo glitch appears to still be causing trouble. Reddit users are reporting that the names of their Pokemon are getting switched around upon making a transfer with MissingNo in the box.
The MissingNo glitch first showed up in Red and Blue on the Game Boy (via Polygon), and it basically creates a non-Pokemon that acts like one in fights, not to mention take up a space in the storage box.
Although you can’t bring MissingNo into Sun and Moon, as players who had it found out, it does switch the names of the Pokemon in your transfer box around. The video above from Clyde BlueSnake shows what happens when you trigger the glitch.
Unfortunately, since nicknames cannot be changed after transfer, affected Pokemon will sport that name forever – so don’t do it.