Language can change, while cultural continuity remains
This happened despite there being practically zero genetic influx from Saxon lands in the past 300 years
What's undeniable is the lingual impact of migrations. Which was also two-way
The recently deceased Iravatham Mahadevan made this point v well in a 1999 interview
"The modern speakers of Dravidian languages are the result of millennia long intermixture of races. There are no Aryans in India, nor are there any Dravidians. Those who talk about Dravidians in the political sense, I do not agree with them at all"