>>58030419 (OP)Golduck needs a (Past) Paradox.
It's a duck/kappa with psychic abilities which makes it a prime candidate for getting an awesome new form that taps into its true power after being so overshadowed by every other Kanto water type for years now. They will be forced to come up with something crazy and this pressure won't be the drive for creating anything else. A mega is just going to slap on a some spikes or some shit, a regional form has an 80% risk of simply being a palette swap, a branched evolution for Psyduck runs into the same issue as a regional, and gigantamax is flat out soulless.
While I'm on the subject, additional candidates for Past Paradoxes are
>Tropius as it could stand to look cooler>Claydol to get a bibically accurate design>Dusclops because the concept of it being a black hole could be further explored>Lickilicky as a way of getting its beta design made official