An item in the Teams release notes tells us that analytics are now available for channels. You can find out how many topics and replies are posted within a channel. You’ll probably know what channels are in heavy use anyway, but seeing how little traffic some channels get is a good way of knowing that maybe your teams don’t need those channels.
The Teams Admin Center has been renamed to remove any reference to Skype for Business Online. The console now includes a set of new Teams usage reports. The reports differ from what’s available in the Office 365 Admin Center and aren’t quite as powerful, but we can expect Microsoft to improve and refine these reports over time.