Microsoft Teams replacing FaceTime in Contact details

I have the iPhone XS - iOS 12.2

Recently my company started using Microsoft Teams, and requires us to have it installed since we're basically an always-on-call business.

I didn't notice it until recently, but for a few of my contacts, the FaceTime icon on the contact details page has been replaced with an icon for Teams.

I thought at first maybe the contact was also using Teams, however when I attempt to video call with them (like I used to with FaceTime), the call fails.

I don't see anything online about Teams replacing FaceTime as the default video conferencing application on iOS, nor was I ever asked as a permission when I installed Teams if I wanted to do anything like this.

Anyone seen this, or have a possible solution?