Dashboards also have the advantage that you don't need to sticky many threads. As soon as you sticky some 3-5 threads, people get banner-blindness and don't read them. Also, like seen on some fora, making 10 threads sticky clogs up the forum frontpage.
With a dashboard, you can sticky one thread and get people to click into it and from there find all basics.
The intended selection of topics so far is based on what things that already are wikis (ie threads that has some volume and where someone has had energy to start collecting highlights in a wiki). I do find destination topics an interesting angle on the dashboard, but there currently are no wikis or major threads about it AFAIK. Also, one must make sure such threads are about AY specific things at that destination, so we don't infringe on the general destinations forum.