Name all the Pokemon in Generation VIII that DO NOT have a variation, regional variation, convergent species (including Paradox), mega evolution, Gigantamax, split evolution, added evolution in a later or to an earlier generation, etc.
Added evolutions only include the pokemon evolved from or evolved to, not the whole line. i.e. Jigglypuff would not be forgotten because it can be evolved into by Igglybuff, in a later generation. Wigglytuff would be forgotten as it has no new direct evolution or pre-evolution..
Regional variants do not count as split evolutions.
Blog with explanations - https://www.jetpunk.com/users/kidibu/blog/forgotten-not-pokemon-explanations