But not for the reason you might think

Its unclear how the cuts are to be apportioned, and how the US intends to enforce its promised cuts, but indications are (its is very unclear, but these from sources, awaiting confirmation):
When oil trade reopens for the week we’ll see how successful the agreement is, so far, at limiting further price falls for oil.
For some context, Saldanha Bay is a vital hub for crude oil storage because of its strategic location in which it allows for transport to demand centers in both Europe and Asia.
This is similar to the story reported by the FT earlier today here. It is said that several OPEC members, including Saudi Arabia, are leaning towards a deeper oil output cut because of the coronavirus outbreak.