Stolarek et al: Genetic history of East-Central Europe...

[leonardo]

This is the progression at FTDNA using their Globetrekker.

Is this claiming the Green is the core area they believe M458 expanded from and blue is where they expanded to?

What is the source of their data? I'm not on ftdna personally

I don't know the "source." I imagine it's the data they have collected on ancient and recent samples. I would think the green is the core and the blue a peripheral presence.
EDIT: I went to the Globetrekker tool on FTDNA and here is what they say about it: "Globetrekker estimates geographical ancestor locations and migrations across the world based on the largest database of high-coverage Y-DNA sequences, ancient DNA results from archaeological remains, and user-reported ancestral locations. These are best estimates and will change over time as more people test their Y-DNA and provide information about their paternal line ancestry."
And here is a statement they released about it in July of 2023, https://blog.familytreedna.com/globetrek...er-report/