It's obviously worse, but it's not a terrible replacement. Gets past taunt which is a plus, but it's less damage and doesn't create a threat. There's probly a better card that will take Cold Blood's place.
Sinister Strike is weak enough that the card has never really been an auto-include in Miracle Rogue. Cold Blood is now a worse Eviscerate - but there is presumably a considerable amount of room between being a worse Eviscerate and being unplayable. While I don't really think that nerfing so many evergreens at the very end of a Standard year is healthy for the game, I suspect that Cold Blood is the card most likely to continue seeing play among all the evergreens that have been nerfed in Dec and Feb.
At that point you might aswell be running Abusive Sergeant. One of the reasons Cold Blood is strong is that it can turn a small drop into an actual threat and sometimes you even get to cheese 4 or 8 extra damage in the early game.