Essentially, yes. A person who renounces U.S. citizenship is generally not able to take advantage of the special visa programs (like the EB5 investor program) to regain residency. Furthermore, their applications for visas, etc., are also (informally) put in the lowest-priority bracket unless they pony up to be placed in the priority queue.

Moreover, any attempt to renounce their renunciation of citizenship results in a hefty tax bill for the period they were not a citizen, as the initial renunciation will be treated (by the IRS) as an attempt to evade taxation. Indeed, merely returning to the U.S. for a period of more than 183 days (one of the tests for residence for taxation purposes) could trigger this result. EDIT: Also note, as discussed below, he would be deemed "inadmissible" for re-entry if he was deemed to have a tax avoidance motive for renouncing his citizenship. The consequence would be a permanent ban from the U.S. (and the hefty tax bill would remain intact).