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Report: Microsoft to face antitrust case over Teams
(arstechnica.com)
This is a most excellent place for technology news and articles.
They bundle teams with o365. The cost to integrate another messaging client is more than simply adding Teams to your already expensive bundle.
It's as simple as this really. It's included therefore a subscribing company can just not renew a slack, Zoom, or whatever contract and say "hey we saved money"
They actually just decoupled teams from o365 in preparation for this exact situation. As of April 30th you no longer get teams with your tenant skus anymore unless you are grandfathered in to the older skus that bundled it.