CRM - Do calls through MS Teams also create logs in my CRM?

Yes, when you use MS Teams to make calls, or to send SMS to your CRM contacts, all these interactions will be automatically logged in the Contact's timeline.
Please note that if the call or SMS happened before the integration was set up or the contact was created in the CRM, the interaction won't be automatically logged.
We don't create contacts in your CRM automatically, as to avoid polluting your CRM's contact base.
Also note that currently Voicemails are not recorded in the call logs.