you should raise this with support. Time zone tables are usually loaded on servers and probably not something admins have access to change.

Thanks! I actually reached out to the support team, and they said we should change it ourselves with css.

oh wow! was not aware you can do this...not sue I would tamper with it though as it may be tough to get all the places where the time zone names appear...would be great if we could suppress that for users and only have it appear on their learning profile...

This should be a product level update. I suspect support misunderstood. 

agree @lrodman