Billed = reckoned?

No, more like "slated" (to be) or 'next in line'

Bills were, and I guess still are, posters announcing the next coming attraction at a theater or a circus. So, if someone, or some county, were said to be "billed as the next superpower" it would be referring to the likelihood of that happening.

Joe(I hope that's clear)Nation

Thanks.

Predicted.

yes.