Change all users to a default PIN for voice mail

Hello @dylanhunt, thank you for your inquiry!

Currently, Zoom Phone has an option allowing you to set the same PIN or a Randomized Pin across your users. This can be achieved by creating a User Template and then applying that Template to users. I've added a support reference guide below. Let us know if you have any questions on this. 
https://support.zoom.us/hc/en-us/articles/360059433832-Creating-templates-for-phone-settings 

At this time, we, unfortunately, don't have an option that would force your end users to change their pin. However, if you would like, we would love to hear your feedback on this, and perhaps we can implement such an option. Please feel free to add your feedback at https://zoom.us/feed.  

I hope this helps! 

Thanks!