https://www.avweb.com/flight-safety/...rspace-review/
This gives a bit of an overview of the U.S airspace.
Isn't this just another variety of "roadblock" airspace ? Quote from article below,
"So, what does happen if you are IFR into a non-towered field and you forget to cancel IFR? See the sidebar for a real story. On the ATC side of things, the controller working that airspace, Class E and G airports, will wait 30 minutes before allowing other aircraft to be released or cleared for an approach. Section 10-4-3 of our rule book states that, “After the 30−minute traffic suspension period has expired, resume normal air traffic control if the operators or pilots of other aircraft concur. This concurrence must be maintained for a period of 30 minutes after the suspension period has expired.”This means that if you are IFR and following another IFR aircraft to a Class E or G airport, and they don’t cancel, ATC will first suspend IFR operations for 30 minutes waiting on the call. Then after that 30 minutes is up, any pilot already waiting to land there will be asked by ATC if they are comfortable shooting the approach. That must be done for 30 more minutes after the initial suspension time.
If you arrive or are already in the airspace and then IFR traffic is suspended to that airport, ATC will advise you as soon as possible. From this point, the pilot determines if they want to divert to another airfield, hold until the suspension is up, or if they are able, cancel IFR and proceed VFR if the weather permits.
If you find yourself in this situation, do your best to make a decision quickly. Once you do land safely, don’t forget your options for cancelling IFR. If not cancelling in the air, you can call the number ATC gave you, or if they forgot you can always call flight service and cancel with them. At fields with a Remote Communications Outlet (RCO), you can utilize it to cancel as well!
You already know your own requirements to enter certain airspace, but now that you know some requirements for ATC to allow you to enter or remain clear of certain airspaces, regardless if you are VFR or IFR, you are better equipped to handle certain scenarios. The non-towered field scenarios happen daily. ATC could be limited in certain cases to tell you what you want to hear, but they do the best they can to help prepare you. At nontowered fields, do your best to cancel IFR as soon as safely possible, and use extreme caution when popping out of those clouds, especially in Class G airspace."