A bit of a dumb title, Nintendo does develop their own emulators to help port content onto newer systems and that's been known for some time.
Virtual Console is an emulator, or rather a series of self-contained emulators that individual games are packaged in. The NES and SNES Mini consoles use emulators to run their games. Hell, even the original Animal Crossing came with its own NES emulator to run playable versions of Nintendo titles you could get as furniture.
It's not "emulators" they have a problem with, it's third-party emulators that supposedly infringe on Nintendo code/IP and the distribution of ROMs, but whether those grievances are legitimate or not is a separate topic entirely.