It's a matter of degree. Of course they learned some things from each other, but did or could the groups have largely similar cultures? The term used in the paper is "behavioral uniformity", which is more than exchanging a few memes. And what does that say about how much and how deeply they interacted? From the abstract:

The south Levantine mid-Middle Palaeolithic (mid-MP; ~130–80 thousand years ago (ka)) is remarkable for its exceptional evidence of human morphological variability, with contemporaneous fossils of Homo sapiens and Neanderthal-like hominins. ... We suggest that the development of this behavioural uniformity is due to intensified inter-population interactions and admixture between Homo groups ~130–80 ka.