Correcting previous post, there were individual assessments made and it was understood that many were outside of IR35.
However, the results of the surveys were not shared, so this is speculation.
For reasons of potential reputational damage and to follow the lead of other financial institutions they just announced that there will be no PSC engagement.
However umbrella and permanent options have been mentioned.
They did not state that contractors were inside IR35 at Discover though.
So it was a particularly defensive move.