If the FDR has xyz accelerometers is it possible the initial blast impact could have registered enough to get an exact blast angle ?
It does, but the FDR only updates each parameter once per second, sequencing through the thousands of recorded parameters every second (a common error when interpreting FDR data is assuming everything in a 'frame' is recorded at the same instant - within a 'frame' there can be as much as a one second shift). Given the time of the initial breakup would be measured in milliseconds, it is highly unlikely the FDR captured anything meaningful. Even if it happened to catch the accelerometer in one direction at the time of the blast, one direction wouldn't help determine the angle - you need at least two to conclude anything.
Similarly, the CVR probably captured a few milliseconds of a sudden loud noise, perhaps preceded by someone saying something along the line of "WHAT'S THAT!"