I don't think R1b L11- was what Maciamo was talking about, but you bring up a good point. Still, R1b L11- doesn't mirror other clearly Neolithic haplogroups in Europe (namely G2a). Was this a distinct Neolithic migration from G2a's in your opinion? I suppose R1b L11- has some similar spots as G2a, but generally, if your map is right, it trends more Eastern, at least. Just drift in favor of G2a as the Neolithic population moved West?
Agreed it's a possibility, but I would see even older subclades in the Neolithic (L23 and upstream). The L11* in Romania and Bulgaria matches the area of the first Indo-European incursions into the Balkans circa 4000-3500 BCE. It may be a leftover from that period rather than from the Neolithic.