This demo uses a primary blue button to allow users to interact with the expand all/collapse feature: https://www.patternfly.org/v4/components/data-list#expandable
Having that functionality in the demo is great, the only issue is that people are considering the use of a primary button in this context a design suggestion. This is not what we want to convey, so we should update that primary button to something else.
Perhaps just a blue link button? but @mcarrano @mceledonia do you have any other ideas?