Z. H. Darkstar
Explorer
Huh. I specifically do want Sneak Attack to work with unarmed strikes. I just have a picture in my head of the good guys sneaking up behind the guard and putting him in a sleeper hold and equate it to unarmed sneak attack. *shrug*
Maybe there should be a proficiency for "unarmed strike as weapons" to allow some folks (Monk, some kinds of Rogue) to stack.
The only way that you'll see this in an official capacity is if WotC decides to bring back multiclass-specific feats, like Ascetic Rogue. If your DM allows for homebrew, then here's what I envision to be the 5e version of that feat.
Ascetic Rogue
Requires: Sneak Attack, Martial Arts
1. Increase your Dexterity or Wisdom by 1, to a maximum of 20.
2. You may treat your monk weapons, including unarmed strikes, as having the finesse property only for the purposes of determining use of Sneak Attack.