If you've worked with Unity before, you know that they're a very developer friendly organization. Furthermore, the TOS changes are merely for show. The fact is that Improbable has been breaking the TOS from the get go, (putting their wrapper around a one time use Unity License, then selling that to multiple people).
Improbable doesn't sell Unity to people. All Unity developers who use SpatialOS use their own copies of Unity. Improbable explained how it all works here.