I’m pretty sure crossing the threshold = the resolution. So “follow all issues to the door” means paying attention when the issue is resolved. Things generally don’t get as much attention during the follow-up as they do during the initial shock of it.
I didn’t see De Vries being replaced so soon, but you’ve been living under a Ric if you didn’t hear about the short leash Marko was giving him. His clock started ticking ages ago and he hasn’t shown anything since then.