Can we only track analytics when using the Stream experience? I don't see view count in Yammer or Teams.
The "Current live viewers", "Views", "Likes" stats only are available for live events created that run through Stream, that is...
Event created directly in Stream
Event created from Yammer and type picked is "External encoder"
Event created from Teams and type picked is "External encoder"
However currently in production the only way to get to those analytics/stats is to go to your event in Stream itself. Any event you create in the list above "external encoder" goes through Stream. So you can find your event in your "My videos" section of Stream.
In a upcoming release we'll add the analytics stats to the producer page in Teams directly. (I can see it internally in a early test build right now. In the teams right panel there will be a new tab.)