For a hollowpoint to expand it has to hit material at a certain velocity to start this process. My personal opinion is this is just more gimics to get the publics money. Even with the new crop of short tube ammo, its an iffy proposition in real life.
No companies really even carried about snubbies until CCW laws swept the landscape, and the popularity of the snubby among people looking for the perfect CC piece became obvious.
I carry a 158 grain SWC in my snubbie, and goe for penetration as a priority. The FBI load was a 158 grain SWCHP. Hope this answers your question.