From someone living near Frankish, Hessian, and Swabian germany, this is still accurate (for now).
I have a Syrian coworker who speaks in the thickest regiolect, and it’s incredible to watch racist old people immediately change their minds about him when he opens his mouth.
I’m also an immigrant and was complaining to a German friend about how I can understand Dialekt, I just can’t respond in turn and I felt like that was a failure in my German ability. She noted that it’s like that for Germans too, which is why it’s mostly older people who have a strong dialect (in the cities).