Maybe they did, but I don't see how that's relevant.
Companies develop products all the time without making any announcements about it until the actual release date.
They didn't "let" anyone buy anything. at the time you made your purchase, you were buying from their current lineup.
I don't see how you would expect Shearwater would advise you not to buy a Perdix, and tell you to wait instead for a product they may have been developing, but havent publicly announced.
Would you go to the dive shop you bought it from locally and tell them that they were wrong for "letting" you buy a Perdix from them and not advising you to wait?
There's a good chance that you got a good deal on Okinawa when you bought your Perdix, so listing it for sale won't result in too big of a loss for you. Assuming you purchased it from a shop in Oki.
I'll be in the market for another Perdix soon.
My point is that I don't think any business is going to turn away a customer and tell them not to buy something now in the interest of waiting for some eventual release.
Just look at the seabear threads to see how long people end up waiting for an eventual release.