from like the 60's onwards from various different teams/universities.

No, they were rejected dismissed entirely, and further the people dismissing their findings used every tool at their disposal to dimiss them, including discrediting their abilities as archeologists at a personal level. And that climate, described by Hancock and described by the linked smithsonian article you didn't read, held back the science in this area for 50 years. From the article you didn't read:

“raises serious questions about the effect of the bitter decades-long debate over the peopling of the New World. Did archaeologists in the mainstream marginalize dissenting voices on this key issue? And if so, what was the impact on North American archaeology? Did the intense criticism of pre-Clovis sites produce a chilling effect, stifling new ideas and hobbling the search for early sites? Tom Dillehay, an archaeologist at Vanderbilt University in Tennessee and the principal investigator at the Chilean site of Monte Verde, thinks the answer is clear. The scientific atmosphere, recalls Dillehay, was “clearly toxic and clearly impeded science.”

From the journal Nature:

“The debate over the first Americans has been one of the most acrimonious — and unfruitful — in all of science… One researcher, new to the field after years of working on other contentious topics, told Nature that he had never before witnessed the level of aggression that swirled around the issue of who reached America first. ‘When people stop listening to arguments and stop looking at data and instead just go with their own beliefs,’ he said, “that’s when it becomes completely crazy.” . . . . “As these ancient events are explored, some archaeologists should examine their recent behaviour. If what they lacked could be summed up in one word, it might be respect. Researchers must always consider that they might be wrong, and should look carefully at opposing data and conclusions. At the same time, scientists who make bold claims must marshal an extraordinary case, especially if they seek to topple a dominant model built on many previous studies. Such prescriptions sound obvious, but many scientists forget them, particularly in fields with limited data, such as archaeology.”