I think "vanity" is the wrong term because their existing credit rating, which they attempt to preserve, impacts all other borrowing (and possibly other agreements and finance vehicles, etc.) that they undertake.

So it's probably valuable to retain that credit rating.

The real issue here is how simple it is to game the rating agency in this way and how the market allows Meta to "launder" this activity through the ratings agency.

This is, in fact, a fairly close analogue to the housing crisis and the ratings laundering that was done with the CDOs[1]. The difference is, instead of drilling down to thousands of mortgages - each with different characteristics - you really just drill down to Meta ... which might not be too risky ...

[1] https://en.wikipedia.org/wiki/Collateralized_debt_obligation

Agreed. I know very little about financing but I’d bet if their rating fell that would trigger some debt repayment clause and the house of financial cards might wobble or fall.

…someone needs to shake the tree and see what falls out, like Peter Thiel did for SVB.