I don't recall the time stone being mentioned as a possible solution. The plan was always using the quantum zone to perform a heist (which implies going in but coming back), gather all of the stones and use them to bring everyone back. That's the plan that Scott comes up with and that Tony initially has reservations about because he isn't sure about how safe it is. Basically he's worried he won't come back to his family. That would all still pan out if Pepper was only pregnant.
The only time he possibly mentions resetting time is when he talks to Steve outside the facility and lays down the rule that he's on board with bringing people back but not losing what he's gained over the years. Again, this could still work if Pepper conceived after the snap. If they go back and change things, then there's a possibility she might not get pregnant. I would agree that this probably wouldn't have the same amount of emotional weight because the audience wouldn't have a connection to a physical character like Morgan in the movie (hence why I mentioned I love you 3000 in my previous post).
But all of this is to say that it wouldn't have been impossible to tell the story without such a huge timeskip. It would have been different for sure and I admit that the 5 year jump was bold and made for a lot impactful moments in the movie (mostly for Tony) but now we're stuck with it and the only character it really benefited is dead so it's just weird to me.