I must be losing my mind.

First, so long as I can remember HQ has always been able to be resupplied.
Second, I don't ever remember Knights being without radar for 4 days. UNLESS it was prior to the uncapturable bases and on a map (such as Mindnao) where knights could be driven away from their HQ and couldn't access it to resupply it.
I DO however remember quite a few years ago where Knights would up a flight of goons to resupply HQ even before the bombs dropped. They did this in addition to the intercept flight of fighters. Most, if not all of the time radar would be down 30 seconds to 5 minutes. I clearly remember people razing the other team for their 2 hour flight and 30 second result.