If they are thinking to increase their BTC reserves it's great but it is again alarming for us because it will lead to more volatility in the market if any fud occurs similar to the LUNA.
Honestly, this is what I'm thinking. Since Luna is also associated to Terra/USTC, I am having that feeling that this could also lead to the same thing as them but it could also be entirely different.
I know that Tether is big and I've got the same feeling on what happened in the past could really lead them to it. It sounds exciting and easy since they're buying Bitcoin. Who knows if it'll be a success and we'll just have to wait what will happen but hopefully, it will be the opposite and it'll result good for them and best for Bitcoin.