Hey Ricky, it's one that the Microsoft community is a little confused about by Microsoft's line is they can't say they support full E2EE.

Here's a good thread showing where we amended the tick to a cross: https://www.linkedin.com/posts/dominickent_team-collaboration-tools-comparison-microsoft-activity-6751842129447809024-ZM83

The NSA doesn't recognise Microsoft as E2EE here: https://media.defense.gov/2020/Aug/14/2002477670/-1/-1/0/CSI_%20SELECTING_AND_USING_COLLABORATION_SERVICES_SECURELY_SHORT_20200814.PDF

But here's a VERY good thread which goes into detail: https://techcommunity.microsoft.com/t5/microsoft-teams/end-to-end-encryption-with-microsoft-teams/m-p/804842