I have been running GOS with Google Play Services sandboxed and most normal social media apps and some bank apps for 3 years now. I am still a Google account user but I don't think that impacted my ability to use Microsoft office on my phone. All that to say I think my experience may be comprable:
For an internship, I used the Microsoft Company Portal app as required by my Ex-Employer (moreso required by the verison of the microfost suite they used). The company suggested using Microsoft authenticator for account verification, however it was not required and I used, and have been using, the Google authenticator past and present without issue for both that work accoun and other stuff.
The Company Portal app is I think what you're concerned about and this is valid as I had issues from time to time. My usage of Outlook and Teams was dependent on this app, and from time to time, the app would fail and not allow me to log in to outlook or send messages in teams. I would continue to recieve notifications during these periods. I cant rememeber if it would fix itself or if I forced stopped the apps and then resterted them, but it meant I would need to log into my work laptop to do work. My experience was somewhat volatile. The internship was only 3 months (last year) and the issues only presented themselves for the last month once a week and each instance until I did troubleshooting as described above. YMMV