A quick google search revealed this article citing USPTO reexamine statistics:
http://pubs.acs.org/cen/coverstory/85/8503cover3.html PTO requires that a patent reexamination be conducted in a manner similar to the examination of a new patent application. During the process, the patent as originally issued remains in place. The result of this inspection can confirm the patentability of the claims, amend the patent claims, cancel some or all of the patent claims, or add new claims to the patent.
According to PTO, the process takes on average about 21 months to complete [...] PTO statistics also show that 74% of patent reexaminations result in at least one of the claims modified or canceled or a new claim added.
At least new claims are also as likely an outcome as cancellation of claims. Also appears as though we are in for a very long ride - hope NEOM can afford the fare.