The problem lies with MetaCritic. They could filter out the shill reviews easily, but choose not to. FWIW I find the similar PlayStation and Nintendo-named websites doing reviews of 1P games on those cringe too, but they have nowhere NEAR the proliferation in the MetaCritic aggregate that Xbox-named and centered review sites do for Xbox games.
It does feel like an extension of the astroturfing campaign, and should be investigated into. Sadly if the industry won't do it, government will have to.
FWIW, I don't think platform holders trying to open up to their community, or the press & media, is in itself a bad thing. But there are levels to it. Microsoft takes it too far IMO; they have a face/mascot in Phil Spencer (and to a lesser extent, people like Aaron Greenberg) which is good in the fact they're a relatable presence, but bad in that they are tied directly to the actual upper management of the gaming division, which ends up creating a cult of personality (which can be dangerous).
It's also one thing to have a relatable face who openly speaks with the media and press; this is something Sony have been VERY bad at this generation because Jim Ryan is just 100% not that type of guy. He's a shrewd businessman, his element is in that environment which is mainly behind-the-scenes. However, buttering up the media and press in return for "favors" to boost reporting and reviews of your platform & games beyond what they otherwise merit, or direct negative reporting towards your rivals, is an unacceptable practice. I don't think Microsoft feels the same way :/