What's more likely?

Disney comitting a massive amount of gross violations of FCC regulations by running a secret and undisclosed astroturfing campaign and that every redditor and hobby site is secretly either a fake bot or in cahoots and being paid off to post positively about the show?

Or people talking about Andor because it's a surprisingly great show in an IP that has gotten a whole lot of trash recently?

Reddit imagines that astroturfing to be WAY more common than it is, and vastly overestimate the value of reddit threads to advertisers.

When we're talking ad campaigns designed to draw tens or hundreds of millions of eyes, no one is going to expend any degree of effort to break the law for the grand prize of... some reddit threads with a few dozen comments.