They have recently adjusted the CP values of damn near EVERYTHING in the more recent update, so how much that changes things overall remains to be seen, but I'm betting that it's related to upcoming changes involving combat and likely PVP as well.
Also if you can, I'd recommend trying to do the Meltan quest by the 27th. There're Pokéstop research tasks that'll get you encounters with Pokémon you need: Excellent Throw = Ditto (catch for part 3), evolve 2 anorith = Scyther (need to have candy to evolve for part 7), hatch 2 eggs = Aerodactyl (catch for part 8). Not to mention, they're spawning all the Pokémon you need to complete it more frequently until then.
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