Bomber64 said:

Bullshit, missingno will always be 000

Missingno actually has infinite numbers, because it can theoretically exist in any ID that doesn't have a Pokémon assigned to it. Generally, one would trick the game into requesting ID #000 through the Old Man Trick.

#000 is now assigned to Victrini (although it's possible the ingame ID will not be #000 and just display #000), so you will have to select another ID to get the equivalent of a MissingNO, unless they added a failsafe.

if you think about it, it has a name. MissingNo might actually have been designed

If it were designed, it would have a sprite. Its sprite is different depending on what game you use it in and the name of the character you encounter it with, and it is always "randomly" selected garble from other sprites, or other sprites with weird palettes.