Now I made a more extensive analysis of the sample and I'm now pretty sure we deal with an individual which has Monteoru admixture of about 1/3 to 1/2, which would fit into the bigger picture of an inhumation burial and haplogroup I2. But for the sake of an argument, just to keep things open, I took the sample for what it is, without assuming, even though I'm pretty sure, it has high Monteoru admixture.
I made a selection of samples relevant to the region and time frame:
One can clearly seee that there is a mixture of one component, which is more Maros like, and another, which is more Monteoru-like. From Encrusted Pottery, that much can be said, the sample is very far away. Because of the mixed character of the individual, the distances are rather bad:
The three closest relevant samples are however Maros, Protonagyrev and Cetina. This shows that even this mixed individuals tends towards Vucedol derived groups, rather.
Third I made a PCA (Europe 2 version) with the relevant samples plus Mezocsat locals (Western fringe Gáva-Kyjatice):
The closest samples are Maros, Protonagyrev, Vatya individuals from the ancients, from the later periods a Hungarian EIA and a Mezocsat local sample get close.
With the Encrusted Pottery group, he has nothing in common, even though he has Monteoru admixture. One can however see, that one of the outliers from Mezocsat has still that Encrusted Pottery-like profile, which proves that this type of population survived somewhere around the Carpathian basin, yet its clearly not related to Wietenberg or Gáva, because those rather replaced it.
What's also clearly visible is, that GAS004, even though he has Monteoru admixture, being strongly pulled towards the EEF pole, towards Bordrogkeresztur and others. This is especially evident if comparing him with Maros and Cetina.
The trend is probably even better visible on the Europe 1 PCA:
He approaches Bodrogkeresztur, especially the outlier No 2.
And that's despite the fact, that he is, in all likelihood, a mix of actual Wietenberg : Monteoru.
I included Noua-Sabatinovka, he doesn't need it, and if he would have had recent Sabatinovka admixture, he would score and plot differently. Therefore my assumption is that just like Nagyrev samples, he is a mixed local and the local component looks very EEF, even more than he is, low steppe, low WHG.
Of course, it would be great to have more samples to confirm this directly, but the abstract for the Transylvanian project already said so - why should they argue for local continuity up to Noua, and this sample has no Noua-Sabatonovka admixture and is too early for that anyway (dated to Wietenberg II period!). Monteoru admixture, that is a different thing and was recognised from the archaeological record in Transylvania already.
Therefore my conclusion is: He is a local, no complete foreigner, but he has recent Monteoru admixture up to 50 percent, which might be part of the explanation, why he got an inhumation burial within a Wietenberg context. I would also like to know, whether the other buried people of the site are related to him, probably from the same mixed lineage. I consider this a distinct possiblity.
But again, the other component, that minus Monteoru, is quite obviously very high EEF and low WHG, and even this mixed individual pulls in that direction already, compared to all the other relevant samples from the MBA.
It is probably worth to mention that we have even more extreme samples in this respect from the record, and again its a from a culturally mixed-foreign context. The Hungarian Bell Beaker samples are all over the place. Some plot like actual Bell Beakers, others like Encrusted Pottery already, They mixed with local high EEF groups, or better, some Beakers were part of that.
This sample looks, overall, very promising for the upcoming samples, insofar as following the trend: A clear decline of WHG ancestry and increase of EEF from West to East within the Carpathian basin:
Encrusted Pottery -> Vatya -> Nagyrev -> Wietenberg. And that can be shown, even with this apparently/likely mixed individual!