The question of actors as classes, including inheritance, was discussed extensively at the end of last year. Raising the topic again when nothing seems to have changed seems unproductive. If this were a green field discussion for a language without existing async code, class hierarchies, and design patterns, it might be a worthwhile discussion. However, Swift will be 7 years old this year and has millions of lines of code in the wild with millions more it needs to interoperate with. Introducing another reference type with different capabilities seems counterproductive at this point
This isn't really true. People just read way, way too much into a single WWDC presentation. Swift is a multiparadigm language, with no paradigm meant to rule them all. It's highly unlikely that protocols will ever reach feature parity with classes in Swift.