Yes. There were a lot of Pokemon that didn't make the final cut. Several of the more famous ones are Gorochu, a Raichu evolution, Turbann, a Shellder evolution, Kurusu, the original Johto Water starter, and Honōguma, the original Johto Fire starter. Many of these were leaked from the Gold and Silver Beta version, or part of the original Capsule Monsters concept. There were also Pokemon altered from their original forms, such as Ivysaur and a great many Generation IV Pokemon.
Source (contains these unreleased Pokemon)
In a different sense of "cut from the games", many Pokemon were not included in Sword and Shield. Approximately 400 Pokemon were in the base game, with the others not being able to be captured or transferred. With the release of the DLC, the number allowed in the games has been expanded, but all 800+ are still not in the games.
