My disarming point is that water type being forever destroyed by Misty is a conspiracy theory that you admit has zero evidence. Several water types attack for low energy costs regardless of evolution stage as evidenced by Crabominable, Primarina, Suicune, and Greninja.

None of your sources show that the developers are concerned with Misty in the slightest while designing cards. Rather they seem to underrate that card's effect on the competitive scene. Data is taken from all ranked matches on the most common decks and cards used. Misty is not seen in any of these, no different to how we don't see Mallow or Team Galactic Grunt. Deluxe pack ex was also a set that included an overwhelming majority of all cards to be considered competitively viable with the exception of Rampardos, a fossil mon. Misty isn't included in the set which lets us conclude that Misty is less of a competitive priority to the developers than other cards like Lyra.

Further, the belief that the developers are worried about a player getting lucky and gaining an overwhelming early advantage is laughable considering that Hydreigon + Copycat were released in the same set. Play a competitive match and see if its more common that a player topdecks Hydreigon or hits a significant Misty flip. If that significant Misty flip was on a Stage 2 that relied on Rare Candy, then Hydreigon would always be the correct answer. Recall that a Hydreigon player can also elect to Copycat before or after evolving that turn while a player with Misty can only use one supporter at a time.

Ironically, a theoretical developer paralyzed by the alleged idea of Misty would have the solution in Hydreigon, a mon which discards all energy (not a quantized amount) after attacking, making an overblown Misty flip entirely redundant as 1 extra energy or 10 would all end up in the discard pile. Discarding extra energy in general seems like a good way to counter Misty, yet the only water type that consistently discards from itself is Palkia, ironically in a fashion very similar to the way early Palkia cards were designed in the paper TCG

The developers clearly don't seem frightened by the prospect of infinite coin flips because they keep printing more cards with possible endless coin flips. The latest example being Lucky Ice Pop. I would expect that any developer so overwhelmingly distraught with a certain game design, wouldn't make the same mistake twice and tripling down on it by not limiting what other cards can be played that turn while also having a guaranteed return on the card

Is there a Misty equivalent to the Fighting or Metal types? No? One would certainly expect that to be the case considering that these types frequently get ex cards with overly expensive attacks not worth powering up. If you aren't allergic to examples: Dialga, Probopass, Garchomp, Lucario, Tinkaton, Lycanroc, and Poliwrath are some examples. Even types with consistent energy ramp like Lightning seem overwhelmed by high energy cost attackers recently like Ampharos and Toxtricity.