I doubt it, they all face far too big of a risk from a financial downside perspective with little to gain other than slashing "corporate overhead" - read redund

I doubt it, they all face far too big of a risk from a financial downside perspective with little to gain other than slashing "corporate overhead" - read redundant positions in things like HR and accounting. On the flip side, if Space-X has a couple of failed launches and loses one or two contracts, their debt would crush Tesla. And vice versa if the 3 doesn't take off like Tesla is hoping. There's almost no risk to them sharing IP between the two companies. And given how tightly they're intertwined from an ownership perspective, I would imagine that will continue indefinitely.