Add a public web scheduler site for teams like in the previous link entreprise https://sched.lync.com/
This web site would be like the existing one for lync entreprise. It permits to schedule a teams meeting with every kind of contact, internal, external, microsoft account or not. The meeting url can be share with everyone. ThIs permit to use teams with a teams account or in guest mode with teams web app.
This is also useful to create a meeting in an organisation and invite internal people with a corporate email (not office365 managed) but no teams account.