Not to put too fine a point on it, the KLAS airport diagram valid 11-Dec-2014 to 08-Jan-2015 says "readback of all runway holding instructions is required" (in all caps).
AIM 4-3-18(7) NOTE : ATC is required to obtain a readback from the pilot of all runway hold short instructions. There is more on it in 4-3-18(9). Can't find anything about taxiway hold short instructions, but of course it could be in there somewhere and the AIM could easily be out of sync with the .65.
I agree that if someone were to get a taxiway hold short, they should read it back and I certainly would do it myself. In fact we just had someone ask a month or two ago about the single dashed line taxiway holding position markings (2-3-5(c)). The whole point is to minimize the possibility of a collision.