Please provide a reproduction of the bug in a codepen:

Please check the developer site for the contextualMenu
https://developer.microsoft.com/en-us/fabric#/components/contextualmenu

Bug Report

Priorities and help requested:

Are you willing to submit a PR to fix? No

Requested priority: Low

Products/sites affected: (if applicable)

Describe the issue:

The separator of the contextual menu is announced separator by narrator. (on chrome browser)

Repro Steps:
-Open narrator
-Expand the dropdown of ContextualMenu (the first variant in which separator is there).
-Try to take the focus to the separator.

Please use the dev site for the repo-
https://developer.microsoft.com/en-us/fabric#/components/contextualmenu

Actual behavior:

Narrator reads the separator as separator

Expected behavior:

Narrator should not announce the unnecessary things in a page. As per aria-label standard also, we should not announce separator.