Well you can see the screenshot from Telegram, in which he asks for money to provide an 8+ review instead of 6.4 or whatever.
Yeah I see it, but that doesn't look like a threat or extortion scam to me.
We all know how most rating websites work, you pay more and you get higher rankings, nothing new about that.
I second this. It's a common practice, but only if you know you can't get a higher score.
E.g. if someone would give Stake a 10/10 and me a 7/10 because I don't have a specific service or provider, then that's cool, I know I can't compete with Stake.
But if someone would intentionally give me 2/10 although we both know that I'm a 7/10, and then asking for more money to get me up, then I would complain.
Additionally, if the person had previous scam accusations then I would lean more on to the "ok I'm getting scammed here" side.