The "Europe First" idea has been around for well over a decade and it is plausible and even seductive; especially so when it was first presented because (at that time) it seemed to explain an origin for sites older than Clovis that were finally forcing a chink in the "Clovis First" armor. An unaddressed and, in my opinion, insurmountable (barring securely dated skeletons) problem with the theory has come up since it was suggested. That problem is DNA evidence. There have been several attempts to establish lineage through DNA testing. The earliest test didn't rule out the possibility of (very early) European interbreeding with Native American populations but later tests, using newer techniques and larger data bases have shown no indication of interbreeding. The tests showed only connections to Siberia/East Asia. For the Europe First proponents, the best that can mean is that, if Europeans did make it to the New World, they did not interbreed with anyone and died out leaving no descendents. Considering that there is solid evidence that modern humans interbred with Neanderthals, and that in more recent times modern Europeans weren't loath to interbreed with Native Americans, no interbreeding seems unreasonable. Given the wide area over which the sites from which these blades, deemed similar to Solutrean, have been recovered, it's unlikely that the culture that produced them simply failed while the Amerindians that followed thrived. If it is accepted that the last two items are reasonable assumptions, it's not hard to see why, lacking human remains to the contrary, a majority of archeologists are skeptical of any Europe First theory. That the theory presents a reasonable possibility there is no question. It could have happened. At present, there is simply no compelling evidence that it did. So, I await developments with interest.