First of all, a post like this belongs in the
Metagame Discussion thread, but I'll go ahead and address the points you made. Regenerator mons aren't even the prime target for WishPort Clefable to heal, it's usually offensive mons that lack recovery or really any teammate that wants to be healthy and lacks recovery options. At this point in time, WishPort Clefable does have some drawbacks that make it less viable than its other sets. Urshifu is a big part in that, as Clefable wants to switch in and counter it, but Urshifu breaks past Protect and you're stick with Wish as your only recovery. The abundance in Knock Off users also hurts WishPort Clefable as again, once those Leftovers are knocked off, Clefable has to use Wish on itself more often, which makes it more vulnerable and slightly easier to punish.
I think Clefable's really good, maybe even a little too good, but you'll need a stronger and more accurate argument to suggest that it deserves to be tested.