No, the Romney move is still not possible in Bezos' shoes. Bezos couldn't have invested in Amazon in his IRA when it was worth nothing:

https://en.wikipedia.org/wiki/Self-directed_IRA#Permitted_in...

> IRA funds are allowed to be invested in private companies. ... The IRS puts restrictions on private equity investments that can be made by an IRA. It cannot purchase stock that the IRA holder already owns. ... In most cases, neither the IRA holder nor any disqualified persons to the plan can be employed by the company while the IRA has an equity position in that company.