Wasn’t that kind of the same idea behind the Aryan invasion theory about how Indo-Aryan languages arrived in North India?
I’m not sure what recent scholarship says, but the impression I got was that the idea was no longer fashionable.
Which rather suggests that maybe the Aryans, as they've been called, didn't ride into India, but maybe they walked out of India!
That's also being supported by a lot of re dating going on of ancient cities/settlements located between the Indus and the Caspian.
The very ancient Dravidian language group is also being reevaluated to see if it is the SOURCE of the Sumerian language ~ and possibly a background language in the development of Hungarian, Estonian, Finnish, some other now extinct languages in Eastern Europe and Western Asia.
The concept that Indo Europeans invaded and conquered everybody else and passed on a higher culture and technology is becoming quite dated ~ they may well have done such things but others were headed the other way earlier!
A lot of this is related to climate change in Europe. It gets warmer and people move in. It gets colder and people move out. Same with Central Asia, and East Asia. There were many fewer people in the past so there were always new lands to invade and settle with a couple of villages. The world didn't get crowded until a good 4,000 years back.
Some day read about St. Gildas. He dressed in a sheet, slept outdoors winter and summer, on the rocks, begged for his dinner, preached total pacifism ~ and was otherwise a Christian saint in the period just before and just after the end of civilization in Western Europe in 535 AD.
He came from North of the Wall in England/Scotland. He had 24 'brothers'. He was on a first name basis with King Ad (King Arthur), and may well have been Merlin's father. He rebuilt the first chapel in Brittany after the great destruction.
He lived during a period when Jain kings and princes in India sent missionaries to the Ends of The Earth ~ the Jains developed the doctrine of total pacifism called Ahemsa. There were 24 'brothers', successive leaders of the Jain movement, up to the time it split from early Buddhism. The missionaries dressed typically in a single sheet.
Recent DNA studies revealed that modern people living in the vicinity of the Wall (Hadrian's wall) had marker genes typical of people from Western India (where all the Jains lived).
The name of the village where Gilda's Breton chapel is located means First Fruit or First Sacrifice in Sanskrit. Gildas means Joyful Servant in Sanskrit.
BTW, the Gypsies came from India.
There appear to have always been people arriving in Europe who started out in India!