That ending came on pretty suddenly – so much so that I suspect the original plan was to animate a 7th season for the final chapters of the manga. Instead they landed up in an epilogue and we’re left to await an OVA with the last manga volume for Major’s official goodbye.
In terms of a dramatic ending for a “dramatic baseball comic” that lasted six seasons this was a bit of an anti-climax – the events of the epilogue were actually much more dramatic than the ending itself. The Hornets lost to Gibson Jr. in the World Series, Sophia went to Japan to babysit Goro even there and generally made a pest of herself. She even presumed to lecture Shimizu that she should break up with Goro if she wasn’t ready to marry him immediately and surrender all of her personal hopes and dreams, as if it’s any of her business. Still, Goro was smart enough to see that as nonsense – and when Shimizu came to him offering to do what Sophia said, he told her to live her life and he’d wait as long as it took.
As for the epilogue, it’s certainly enough to tell us the final chapters of the manga were wowzers. We have an eight year time skip, after which Toshi has come to America to catch for the Hornets and Keene is now Gibson Jr’s teammate. Watts is the manager of the Hornets, and Shimizu is about to give birth to she and Goro’s second child – just as Goro is about to close out the 7th game of the World Series for Indiana. And all of this plays out over “Road of Major”‘s version of Kokoro E – the original OP that was brought back this season in remixed form. That was a fitting and highly effective way to close the series.