I don't see any action being taken on Necturna until Sketch is useable in game and we know with certainty how it works. Once we know its mechanics, we'd rollback the Gen 9 update and reintroduce Sketch along with any other changes (for example, if we'd still need Necturna Clause).
CAP does not accept personal creations. This refers to any idea for a Pokemon that already has predefined typing, stats, abilities, movepool, name, art, pokedex entries, weight, height, or even generic themes such as "rabbit" or "angry". These facets of a Pokemon are all decided through community discussion in CAP during the CAP process. If you think you have an idea for a Pokemon that does not define these features, you may have a concept. CAP bases our Pokemon around concepts that look to explore the mechanics behind Pokemon and we take open submissions whenever we start a new project.