If the patent holder dies, the other owners share equally in dividends from the deceased. If four of the five patentees die, then the patentee left alive gets 100% of the patent. That remaining patent holder is the company Freescale Semiconductor.
Patents aren't tontines. When a patent holder dies, their share of the patent is goes to the beneficiaries of their estate, unless their will specifies otherwise. But that's irrelevant because Freescale Semiconductor was
already the sole holder of the patent before the inventors died: as is usually the case, the employees' contracts specified that any patentable inventions created through their work for the company are the company's property.
Who owns Freescale Semiconductor?
The answer is: Jacob Rothschild
Jacob Rothschild does not own Freescale Semiconductor. He's on the board of a company that owns shares in Freescale Semiconductor, but that's not in any way remarkable: many rich people are on the boards of many companies that own shares in many other companies. There's no conspiracy here.