Microsoft has just released a preview of a web service to help (and improve?) customer experiences with managing Office 365 Services IP address upgrades.
You already well know the recommendations/requirements/best practices in term of accessing Office 365 Services as well as the public website listing (and providing RSS feed and XML/PAC files) here http://aka.ms/o365ip.
Now, you should start using this web service (as it will eventually replace the website mentioned above).
You can access all the available documentation from here https://support.office.com/en-us/article/managing-office-365-endpoints-99cab9d4-ef59-4207-9f2b-3728eb46bf9a#ID0EADAAA=4._Web_service&ID0EACAAA=4._Web_service
In addition, the endpoints publication comes with an additional information to identify action to be taken
- Optimize for a small number of endpoints that require low latency unimpeded connectivity which should bypass proxy servers, network SSL break and inspect devices, and network hairpins
- Allow for a larger number of endpoints that benefit from low latency unimpeded connectivity. Although not expected to cause failures, we also recommend bypassing proxy servers, network SSL break and inspect devices, and network hairpins. Good connectivity to these endpoints is required for Office 365 to operate normally
- Default for other Office 365 endpoints which can be directed to the default internet egress location for the company WAN
Benefits for administrators from using this web service and the new categories include:
- Automation of Office 365 endpoint data and changes publishing
- System readable data for direct network device integration that is also script friendly
- Data available in JSON for scripts or CSV format for Excel
- Includes the first release of new Optimize, Allow, Default categorization of Office 365 endpoints
- Includes ExpressRoute routable flag for each endpoint
- Version change notification published alongside the data
- All provided attributes are supported by owning development teams
As final reminder, please also review the Office 365 network principles to ensure you are always up to date https://support.office.com/en-us/article/office-365-network-connectivity-principles-76e7f232-917a-4b13-8fe2-4f8dbccfe041