TikTok has declared it will be collecting biometric data:
“We may collect biometric identifiers and biometric information as defined under US laws, such as faceprints and voiceprints, from your User Content. Where required by law, we will seek any required permissions from you prior to any such collection."
What is key about this statement is that TikTok does not specify if the “US laws” are state or federal, and only a few US states have biometric privacy laws at all. This means that, if TikTok only has to obtain consent where “required by law,” users in most US states could have their biometric data collected without being asked first.