Can the Apple T2 chip be used as a TPM to enable BitLocker?
No, the T2 cannot in any way be used as a TPM for BitLocker. TPM for BitLocker is not a generic term for any type of trusted platform module, but rather it needs to be specifically the Intel TPM specification (latest version is 2.0). The T2 chip does not work in a way compatible with the TPM specification.