Standard boiler plate legal language. They already have an agreement in principle, which means they already have a framework for what what the settlement will look like. The leave is to iron out and document the details. The court is always going to proceed cautiously until the final deal is signed.
One other point, this is a Stay, because the parties jointly agreed that they have a settlement. As with any negotiation, something could come up at the last minute and derail it, but I personally believe that highly unlikely in this case.