From here:

Migrations of some Maykop into Yamnaya territory, accompanied by the transfer of knowledge and language, still happened, Wang’s team suspects. Occasional migrations north through the Caucasus to Yamnaya grasslands fits a scenario in which the ancient homeland of Indo-European language lay among Anatolian farmers, the researchers speculate. If they’re right, they have resolved one of the thorniest issues in the study of languages. But the long-debated origins of Indo-European tongues remain uncertain.
Anybody else as confused as I am? I thought there were only two remaining camps - the Southern origin associated with the source of Steppe CHG and the indigenous Northern Steppe origin. But now, it looks like Max Planck is seriously proposing an origin with farmers.