Availability is not used, but influences sessions shown to public
In order to have a session appear in the public program, the availability of each presenter needs to be set. By default, new accounts have no availability, so they have either to be entered by the user itself or by the organisers. This process is a burden for the user and error prone when done by the organisers. The result has been that some sessions don't appear in the program, and you can only notice it by comparing both internal and public programs, or by checking if in the internal sessions page no notice is given about missing availability of the presenters.
I suggest we completely disable the availability feature if there is no specific need for it from conference organisers, or make it modular.