There appears to be no CAS data in FR24, only GS,
I think that CAS speeds could not be conveyed by ADS-B, as CAS is unique to each airplane type, and configuration. Though they were reportedly doing stall testing, where CAS is a factor worthy of consideration, at faster speeds the IAS to CAS difference for the Grand Caravan is zero, so not a factor relative to IAS at this point in the flight. The ADS-B data shows 176 knot groundspeed at roughly the same time as a 9400 FPM dive. So it may have been flying at an IAS faster than the 175Vmo. If G is added to that (like pulling out of a dive), the airplane is getting into a tight corner of the envelope.
As the last reported data point is still at considerable altitude, I infer that the ADS-B output stopped. Perhaps if the airplane broke up in flight, the ADS-B transmission stopped at that point in time, rather than when the airplane struck the surface, for which there is no data point. The last reported position point, and the location of the fuselage on the ground are 1850 feet apart, and the wing 650 feet to the right of that track.