With news media, sports teams, etc., all pushing how interesting FaceApp is, lots of people are using it. However, people are giving up much more personal data than they realize by agreeing to the terms and conditions of the app. FaceApp was developed by a Russian firm and there are indications that the app has multiple compromises and security concerns. At a minimum, you give license to the app creators to use your image(s) in any way the see fit. They can create a fake profile using your face, or worse.
While Facebook is largely used for personal reasons, many companies use Facebook to connect to clients and participate in viral campaigns to create brand buzz. CyberSafe Work strongly discourages the use of FaceApp.