I've been following this rather closely as a company who provides backend services (so we're classified as a 3rd party service)to studios in the industry, many of whom use Unity. I'm rather surprised by this about-face, especially considering Unity had the upper hand in negotiations with Improbable. Pleasant surprise, and a much needed one in the games industry where locked-down tech is often the norm.
So does this mean Improbable can continue operating SpatialOS with Unity, or what?
Good move on their part, but the whole saga is a reminder of the risks of using non-free software, especially if it's a subscription. At any point the developers can pull the rug out from under you.