Has a life raft ever been successfully deployed on a modern commercial flight?
Passengers used rafts to get off the plane; news.com.au
Miami Air Flight 293 (3 May 2019)

More than 140 passengers have managed to escape from a plane crash as a Boeing 737 jet slipped off a runway and into a river. (news.com.au)

There is a list on Wikipedia for water landings, not counting non-jet and not counting overruns, and by checking photos, it seems none used cabin-storable-rafts. The accident shown and linked above is a runway overrun (although it was not excluded from the criteria listed).
This article also confirms the rafts came from inside:

Eric and the pilot wrestled one of the six life rafts out the forward cabin door, down the evacuation chute [i.e., slide] and into the water.