Can anyone with an A5 account see each others Bookings calendar in an O0365 organisation?

We use O365.

3 of our users have just started using it and noticed something a little odd in that they appear to be able to see other people’s booking calendars (i.e. beyond the three of them). It sounds a little like anyone with an A5 licence may be able to see other A5 licence-holder’s booking calendars…

Is this correct?