Well, you don't have to be a "top" starting pitcher to pitch a no-hitter!
In some ways what's old is new again. With openers and tandem starts and swingmen and, especially, starters pitching out of the bullpen in the playoffs, you have more double-dipping (and if you are a starter in a opener game your stats count as being in relief), and less inning-based relief specialization to boot.
The no-hitter part would be the rarer element of the equation, whether it was pitched by an ace or someone forgettable (like Bud Smith, who also never earned a save).
Ryan, Bunning and Carlton would all likely make post-season relief appearances in the game as it has been for the last 10 years.