One can hope that they'll make the attempt regardless. Alcor's position is to carry out their directive from a member regardless of third party opinions on viability where they can, as having the reputation for doing this minimizes the very real problem of interference from family members (for reasons economic, religious, etc). Also it is very hard to say at the time (as time is critical) how much damage is done via fatal brain injury of this nature, and of course at this point next to impossible to say what that will do the the odds and difficulty of future restoration.
Brain injury kept Roy Walford from being cryopreserved, though there it was clearly an extension of his own thoughts on the matter: http://www.cryonet.org/cgi-bin/dsp.cgi?msg=24045 I see that as a terrible shame; it is guessing in advance as to the limits of what can be restored.