If the Chinese had knowledge of the Americas they’d have been the ‘discoverers’ in mondernity.
Without written continuity it’s hard to credit discoverers…
The potential of lost written history is fascinating to me. The Phoenicians of Carthage had boats which were capable of crossing the Atlantic and were known to take journeys well past the straights of Gibraltar, but a lot of their written history has been lost thanks to the Punic wars of Ancient Rome. It would be a fascinating lost episode of history if the Phoenicians "discovered" the Americas well before Vikings or other Europeans did. For all we know, this could have happened but accounts were simply lost to time.
Discovered (for the first time by the "Old World"/Known Written Records)
It's implicit.
Not unlike how we don't discount the extant aboriginals of the Americas being here "first" just because they (generally) aren't actually the descendants of the first human populations that came here (but rather seem to have committed genocide on those people).
It's implicit through context.