My view is that since we're all eternal beings (given my LDS belief in an eventual universal resurrection prior to Final Judgment), the effects of any and all sins still apply no matter what the moral dilemma setup regarding this temporary mortal life may be.
Somebody else already framed the idea earlier: if we're going to grant him this experience because it will supposedly be otherwise denied to him due to impending death, how many other experiences of any type should we be willing to grant him now that he might miss out on otherwise? If one "sex worker" is good, why not three or five at once? He'll never have the opportunity to go to war and kill somebody, either; should we give him a gun and encourage him to "off" somebody so he can have that experience, too?
What I was referring to was a sense of minor personal moral acts that we usually avoid because of long-term danger or harm to ourselves. If there is no long-term anymore it becomes less problematic for various "mild" sins, such as say gluttony or a sexual encounter, or having a few drinks - stuff that we'd deny or restrict to people who were looking forward to a full life.