I view the O-1 as laying the foundation for the EB-1A. It's like your outline or first draft. It's super helpful to have your basic categories and narrative laid out in the O-1. The O-1 approval also provides some validation that you're on the right track.

You can then construct your EB-1A by fleshing out the categories with even more high-quality evidence (media articles, awards, salary, etc.), and perhaps adding a few more categories.

Unless the O-1 package was very strong, I wouldn't just resubmit it as an EB-1A. I'd take the time to amplify and strengthen it.

There's really no connection between the two because although the criteria are similar, the standard for an EB1A GC is much higher so there are many people who qualify for O-1 who won't qualify for an EB1A GC.