With the GA of Atlas search indexes on views, i wanted to update some of my existing search indexes to use views.
Then i noticed that at the moment it is not possible to update the base collection/view of an existing search index without downtime.

You can only create a new search index with the new base collection/view and then update your applications to use the new one.
Or you delete the existing index and create the new one with the same name.
An option to change the base collection in the atlas ui would be helpful in these cases.