Subscription to /teams/getAllChannels/getAllMembers (beta)

Hi,

We've got a couple of questions regarding the subscription to "/teams/getAllChannels/getAllMembers (beta endpoint)" (official doc).

1. This subscription is NOT a metered API, right?

2. Is there any limitation of the number of notifications we receive for the subscription to this resource?

We are asking because Metered APIs and services in Microsoft Graph is saying "Teams conversationMember change notifications" is a metered API. On the other hand, Get change notifications for membership changes in teams and channels using Microsoft Graph seems to be saying it's NOT a metered API. Also, the same doc is saying Subscribe to membership changes in all private and shared channels of a particular team is a metered API. 

Thanks!