Yes, you cannot be compelled to testify against yourself, but Microsoft is under no such obligation when served a warrant because of third party doctrine. Microsoft holding bitlocker recovery keys is considered you voluntarily giving the information to a third party, so the warrant isn't compelling you to do anything, so not a rights violation.

But, the 5th amendment is also why its important to not rely on biometrics. Generally (there are some gray areas) in the US you cannot be compelled to give up your password, but biometrics are viewed as physical evidence and not protected by the 5th.