Earlier quoted context omitted.
I think you underestimate the effect of repeated subtle messaging thrown into an otherwise innocuous storyline. If it wasn't effective, Coca Cola wouldn't have paid to have their product barely visible in the background of a scene in War of the Worlds, for example.
I don't estimate it highly, you're right about that. For your specific example, consider some other factors besides the intrinsic effectiveness of ambient product placement: (a) Coca Cola employs many thousands of marketing people who must, to justify their salary, come up with venues to feature the Coke brand. (b) Mass marketing is notoriously terrible with metrics, so it's not an extraordinary claim to suggest that…
My biggest argument against media consolidation, though, is that I simply don't trust any one entity with significant centralized power. While Disney+Lucasfilm is probably a pretty good fit for business and entertainment reasons, the sheer size of the various conglomerates is astounding.
And don't think for a minute that there isn't blatant propaganda in some TV shows, even if the propaganda isn't coherent within a single media conglomerate. The example I found most bothersome was the justly canceled TV series "V", which had extremely overt xenophobic allusions to issues of the day, like illegal immigration and foreign policy.