If anything, USDC has been reducing its risk profile from what I'm seen. Recently they announced they will be replacing all of their remaining corporate-bond-backing with USD cash and US treasuries. Source for your claims to the contrary?
The August 2021 change seems to be in response to a disclosure, that revealed more about USDC, than had been known in the past. This is a move toward more transarency and accuracy, not in USDC becoming less backed.
And CoinGeek is a notoriously anti-decentralization media outlet. It's a mouthpiece for BSV, whose founder, Craig Wright, has called for anonymity to be abolished in cryptocurrencies, and for miners who process decentralized exchange transactions to be jailed.
There is no indication that this is due to some recent misbehavior by USDC's issuer, as opposed to an independent decision by the SEC to subject stablecoins in general to its control.
