We shouldn't be bothered about the non-scientific outcome of the results for two reasons. One everybody is an immigrant at certain point if you go back in time sufficiently. The Europeans are a mixture of native hunter gatherers (who at some point were also intruders to the region), middle eastern farmers and a third wave which is still being investigated and which probably brought IE languages. Does it mean it is the end of European civilization. Even the Onge/AASI and postulated Iranian farmers are immigrants to the land which is thought to be through the sea route from Africa for the former. Second, as I have mentioned above more than 95% of the Hindu liturgy has sub-continental context which doesn't change irrespective of what genetics says. We should take this only as a scientific project and not fall into the trap of politics which is what the Left and a section of Western Indologists want.
I think those people did exist and there was to and fro migration. I think the timlines are off. I don't know why it has to be specifically from the Steppes. My considered opinion.
I could care less where my genes come. They could be 100% English for all I care. It's only when you start parroting that 'Aryans' gave my civilization culture, language, and that it was oppressive that I have a problem. There is 0% evidence for this but the genetics is being used to reinforce these bigoted linguistic ideas. If it's a genetic paper, keep it genetic. Don't start monkeying around with linguistic nonsense.