Microsoft has announced SMS texting for Teams Phone with Calling Plan

Admin info: [Planning for SMS in Microsoft Teams - Microsoft Teams | Microsoft Learn](https://learn.microsoft.com/en-us/microsoftteams/sms-overview)

User info: [Send and receive SMS in Microsoft Teams](https://support.microsoft.com/en-us/office/send-and-receive-sms-in-microsoft-teams-a7d163cb-3562-4f4a-b1c1-81c722c1a0f1)

Requires the Teams Phone Calling Plan (aka using Microsoft as the phone provider).

You'll have to register a campaign to meet regulations. But it looks like Microsoft has put in place some automation to help with opt-in / opt-out, which is nice. There are also quite a few limits on usage / number of lines.