As part of this the definition of what dfx recognises as mainnet was changed. dfx now treats https://icp0.io as mainnet. If you change every https://ic0.app to https://icp0.io things should work again as before. If you’re wondering why ic0.app is no longer recognised I don’t have a good answer. We probably should have kept that in
In case you’re interested: here is how the detection is defined