Microsoft Office Security Feature Bypass Vulnerability

Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.

What kind of security feature could be bypassed by successfully exploiting this vulnerability?
An attacker who successfully exploited this vulnerability would be able to view Personally Identifiable Information (PII), bypassing the "ThisDocument.RemovePersonalInformation" expected functionality. The attacker would need to first gain access to a document protected in this way by the target.

According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?
A attacker would need to make use of the affected protection and then make the file accessible, either through direct file sharing, posting the file online, or another avenue of access.

Security updates
https — https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
16.0.5317.1000 — https://support.microsoft.com/kb/5002184
16.0.5317.1000 — https://support.microsoft.com/kb/4493152
15.0.5449.1000 — https://support.microsoft.com/kb/4484347
15.0.5449.1000 — https://support.microsoft.com/kb/5002187