First, there can be a big power discrepancy in cases where free product is provided for review purposes. It's different if you are part of a traditional media outfit and have a significant, steady readership. But for someone like this, there can be a lot of pressure to give very favorable write-ups.

Second, this wouldn't be the first time someone did a paid promotion without noting it was paid. I don't know anything about this guy, so I'm not accusing him of anything. I'm just saying it's naive to think that everyone is always highly committed to playing nice with the FTC rules. (See game streamers and their odd tendency to open tons of 'loot boxes' on stream & get significantly better results than expected.)

Finally a lot of the copy reads like it's straight from a press release, with capitalized words and everything.

Whether it's enough to constitute an ad in a regulatory sense, I don't know. But you can be advertised to without the source being a literal ad according to a legal definition.