Microsoft Excel Remote Code Execution Vulnerability

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

How could an attacker exploit this vulnerability?
An unauthenticated attacker who successfully exploited this vulnerability could gain code execution through convincing a user to open a malicious document at which point the attacker could execute arbitrary code in the context of the user.

According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?
The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. This means an attacker or victim needs to execute code from the local machine to exploit the vulnerability.

According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?
A user needs to be tricked into opening malicious files.

Security updates
https — https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
16.92.24120731 — https://go.microsoft.com/fwlink/p/?linkid=831049
16.0.5478.1002 — https://support.microsoft.com/help/5002660