I would guess it wasn't any one specific person as it was a team and during that they happened to noticed this and that and made a tweak to a few.That seems to be the general principle. As a consequence, moves like Psychic Terrain and Pollen Puff are entirely cut from the game because nothing learns them under this philosophy. One oddity we discovered earlier in the thread was Nidoking picking up Sludge Wave by level-up, which is good news for the LO Sheer Force archetype but downright bizarre in light of so many other Pokémon losing historically important moves (e.g. Altaria's Dragon Dance). You may also be aware that Toxic returns as a TM but sees greatly restricted distribution compared to any prior game where it appeared, which we can only assume is a conscious decision. Someone behind the scenes selectively tinkered with these things at their personal discretion, and I doubt we'll learn the full rationale unless that person is identified and interviewed.
But I also assume they didn't have a lot of time or experience in general, so you get significantly more things like not reimplementing the moves Pokemon lost because of TM/TR in SWSH or making up for a lost move.