I see this as not much different than those Whites who are always claiming that they were here in America before the American Indians. Idiots come in all colors.
Pre-clovis sites are finally being acknowledged, even though my 'heretical' archaeology professor in the '70s said humans on the North American continent likely went back 30+,000 years.
It appears even that (wild-eyed estimate at the time) may be insufficient to adequately describe the scope of human existence here.
As for European presence here, who knows? One thing is certain, that people of almost all cultures had at least some members of their societies who travelled, whether out of curiosity, for trade (profit), or conquest.
I think scholars have grossly underestimated the extent in an innate desire to portray history as a linear progression, and underestimated the setbacks along the road to present development as well, despite the ruins of technologically capable cultures which stare us in the face.
Somehow advancement has been equated with technology, and not a question of whether the technology was appropriate for the time and place.
Much as 'finding something the last place you look' works, the inertia against developing unneeded technologies with resources otherwise put to more imminent use persists to this day.
Human nature has little changed, the same motivations and contrary forces exist today as have been since the dawn of time.