Create Team: Add property mailNickname
It sould be possible to set the property mailnickname when creating a new team (POST /teams) like it is possible with the powershell module (https://docs.microsoft.com/en-us/powershell/module/teams/new-team?view=teams-ps)
Laura Kokkarinen commented
Being unable to specify a value for this property (or rather, the value being completely ignored) is not that big of an issue in regular tenants. In those, we can first create an Office 365 group with our desired mailnickname, and attach a team to it afterwards.
However, the problem becomes a real issue in education tenants when you want to create "class" teams. For those, we need to create teams with the out-of-the-box "class" team template, which by default creates a different kind of an Office 365 group in the background. We can't attach a "class" team to a regular Office 365 group.
When creating a team doesn't allow us to specify a mailnickname by ourselves, any team name that contains non-English characters will end up having an unreadable email address/internal name/mailnickname.