Again, these aren't the best case reviews... not even close.... and the author is non-responsive when you ask questions...so overall it is sub-par at best to me as well. But they are not paid shills. Move along, boys.
In terms of whether money changes hands with the express purpose of that money prompting a good review? No, I don't think so either.
In terms of whether the motivation for this rubber-stamping exercise is financial, and it is understood to mean that a bad review would endanger potential revenue or access to sample products in future? I very much believe that is the case.
This is also not without precedent here on TPU either - for example Cadaveca once said rather too much on this topic when he admitted that once upon a time, he gave a motherboard a perfect 10 score (when TPU still had scores), and ended up incurring the ire of motherboard manufacturers, who refused to sample TPU for additional motherboards due to there being no possibility of obtaining a higher score than the competition.
Larger manufacturers with reputations to protect, don't send out product for no reason. They expect to get a boon in terms of exposure and positive coverage. Outlets that don't provide those things don't get sampled again, at least for a period of time. See: GN slamming the CM H500P, being blacklisted by CM's press contact, and only receiving samples again after giving positive coverage to multiple subsequent iterations of the original case that were purchased using GN's own funds instead of being sampled. Now of course, GN are quite happy to take that hit and carry on doing what they do, but a lot of outlets play very buddy-buddy with manufacturers in order to ensure they can stay afloat and publish new content without the overheads of having to purchase that product.