Well, for one a lot less inventory would obviously change housing prices
Why would there be a lot less inventory? The investment group will want to sell it, so it moves from the banks must-sell inventory to the investors must sell inventory.
They may want to rent them out, which could lower inventory, but it would do other things. It would put downwards pressure on rents, with a flood of new rentals making other investors less likely to buy. More potential buyers will rent instead, reducing the pool of buyers. Either way, unless foreign investors are purchasing San Diego vacation homes for personal use I don’t see what impact they’d have on prices.