Really? I didn't get that at all.
What I saw was a post giving negative opinions on various aspects of AWS, and stating that AWS' offerings are available elsewhere. There was an example given, of a previous project where he'd switched away from AWS to dedicated physical servers (at an unnamed provider). There was no suspicious boosterism/puffery in the direction of his own employer, like you generally see when a shill is trying to get away with something.
In fact, it seems like the only real mention he made of linode was in the disclosure that he kindly added, pointing out that he worked there and was therefore biased. Most ads don't bother to do that.
If this counts as an ad, then by those standards nobody could ever post in any thread covering the industry in which they work.