>>> does Grunch automatically update its repository database?

>> No.

> Grunch databases get updated by Grunch aslong as someone bothered to update them.

As far as I can see, the current version of the official Grunch repository database (i.e. the database which also contains the list of known 3rd party databases) is more than a year old, and that database seems only contained in the Grunch archive and not available separately online for easy and fast update by geit. So yes, the official Grunch repository database gets updated by Grunch every time geit is bothered to update it, which is not very often it seems. That is far from the automatic repository database update process relyt knows from GNU/Linux, as indicated by the MorphOS SDK problem he reported.