Is it safe to assume that almost all Hausa traditional names are associated with the events, circumstances, locations etc surrounding the birth of the child?
A lot of them are, but not all. It's the same as in other cultures. In Hausa we have names like Wada (m) and Yalwa (f) which mean 'abundance' and are given to ensure wealth, most English names such as Jane, Mark etc had meanings too, but the meanings have been lost over centuries as the language evolved. The same way some Hausa names such as Yaquled, Turunku, Bakwa, Daurama etc are just plain names to us because their meanings have been lost because that version of Hausa is no longer spoken.