Actually, that's a better fit! Because the Mako and Encrusted Pottery group being an outlier in the region, while surely representing something strong and well-established in or around the Carpathian basin for a time.
But if you look at the PCA, you can see that there was a decrease of this WHG ancestry when the Tumulus culture groups attacked and pushed the Pannonians to the East. They then fused and mixed with Epi-Corded and more Neolithic shifted elements, especially at the Upper Tisza, but its possible, considering the close relationship, that this was not the end to the North, but the areas of Komarov and later Lusatians got affected too.
So we get a mix of very Neolithic (Bulgarian-like), Epi-Corded (well, CW-like) and this Mako-like elements in North Eastern Pannonia/Carpathians.
You see the decrease from Mako - Encrusted Pottery - Pre-Gáva/Halva - Gáva - Mezocsat/Prescythian/Thraco-Cimmerian, that's a constant decrease of this WHG rich element in the mix, but it doesn't disappear. Especially the Kyjatice sample BR2, the brother group of Gáva is interesting, because it looks like having gotten more of the Füzesabony/Epi-Corded influence, which would be just logical, because its to the West of Gáva and its predecessor, Piliny, being influenced by Füzesabony.
Compare again, its amazing how you can see this decrease of WHG, and at the same time that the two Füzesabony (late Otomani with strong Epi-Corded input) samples are "ultra-Slavic" on such a PCA:
https://ibb.co/jzZs1Hs
Pre-Gáva/Halva is halfway between Füzesabony-Mako-more Neolithic Pannonians. So really that mix which emerged in the North East after the Tumulus culture push. Most of Channelled Ware/Gáva proper has already a much decreased Epi-Corded contribution and being more between Mako and more regular Pannonians, mixing with an "Illyrian-like" and more Neolithic elements depending on region.
Also note, that
Mako is not extraordinary in Pannonia, the very important Encrusted Pottery (HRV_Jag_MBA) group got it too and they are not just outliers, but the regulars of this ethnicity, even though this is from their Southern refuge, when they evacuated to Northern Croatia under Tumulus culture attacks pressure! So they moved South, but were originally somewhat more Northern before. We can also see that some of them began to mix with the locals and these mixed individuals being more Neolithic shifted in comparison. But the whole core plots around Mako.
In this way, a stronger influence from this direction, not just Mako-like, but combined with fairly South Eastern Neolithic/Copper Age/EBA elements (more BGR-like!), like its more typical for Pannonia than more Northern or Western regions, would make perfect sense.
Since you said, that, it actually strengthens the hypothesis, that this element came, in a mix, from in or close to Pannonia to the Baltoslavs and the Slavs got just more of it, probably also in later times from Daco-Thracians/the Carpathian zone through persistent gene flow. Or the Balts got less of it because they are more local, instead of the Slavs having that much more admixture.
Tollense too is unlikely to be a pure representative, but they surely mixed on the way. My impression from the Balkan archaeological situation is that these Eastern Urnfielders picked up locals en masse, but primarily females.
As for the uniparentals, we don't have that much if anything from the Eastern groups. Like Komarov is really interesting, as is the Lusatian Eastern fringe. I don't think they have to be the same. Look at Kyjatice and Gáva, they were like brothers and so close culturally, that its oftentimes not possible to differentiate their artefacts within the Channelled Ware sphere. Yet they might differ both autosomally and in uniparentals in a quite signficant way.
The only strange thing is that the most extreme individual in this WHG-shifted direction is the Mezocsat outlier, at a time even among the descendants of Gáva (I think this is what these other Mezocsat samples are about) the WHG ancestry did largely decrease to almost modern levels. That's peculiar and needs an explanation.