Hi Christopher
My knowledge on this is limited, but off the top of my head, I would say no, you can't create an account through this method. As you said, Shibboleth is just about authentication. You could setup a link to the separate online registration, and have it in a category that would authenticate right off the bat, but people might abuse that. There should be a staff member that moderates registrations...until Koha can do it on it's own. That is not likely to happen if multiple accounts can use the same e-mail address.
As Jonathan Druart pointed out you just need an "autocreate" set to 1 in the Koha configuration file (apart from the mapping of course). This is (somewhat sparsely) documented in https://github.com/Koha-Community/Koha/blob/master/C4/Auth_with_shibboleth.p... This feature was introduced in https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=12026 (Shibboleth auto-provisioning - Create) We tried it, it works. Another thing is syncing, we're still struggling with that though. Best wishes: Michael -- Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz T 0041 (0)61 261 55 61 · E mik@adminkuhn.ch · W www.adminkuhn.ch