Just to clarify, you do know that he doesn't have to have a FSIQ that's 145, right, Tall Boys?
On the WISC, if the GAI, PRI, or the VCI cross the 145 mark, it counts. (The same with the SB, though I forget the abbreviations for those comparable indices...)
I think it's smart to apply if a child is close and you think the program would be helpful. Worst case, you get a "no," and they keep your file so that you just have to submit any new info if it becomes available. It's not wasted effort. Best case, the child is accepted.
And BTW, a "no" doesn't appear to harm future chances. I personally know a number of families who applied and got a "no" or "need more info" initially but were later accepted. It's not at all uncommon from what I can tell.