According to Trezor:
The community has spoken, and once again, we deliver! We are thrilled to announce that the beta version of our new Bitcoin-only firmware is now available to download for both Trezor One and Trezor Model T. We aim to introduce a stable version of Bitcoin-only firmware in the next month’s release.
From now on, we will be producing four different versions of firmware — regular (full altcoin support + U2F/WebAuthn) and Bitcoin-only, for both Trezor One and Model T.
We have created a customized version of both our firmware and Wallet designed for everyone who supports the idea of Bitcoin. Every Bitcoin maximalist can now enjoy the Wallet interface with nothing else but Bitcoin. All the features of Trezor One and Model T available just the way you like it; Bitcoin only.
https://blog.trezor.io/sources-say-orange-coin-good-new-bitcoin-only-firmware-now-available-47be0b611a4d