A reading of the law would seem to indicate that yes, in fact, you can simply remove the offending item(s) from the state and thus no longer be in violation of the law.
The problem is that apparently the people at the EOPSS didn't read the law, or have overactive imaginations. The letter they sent to every FID, LTC, and MG license holder in the state implies that turning them in to police for destruction is the only avenue for legally disposing of evil bump stocks and trigger cranks.
"Because the law does not allow for transfer or sale of these prohibited items, if you currently possess a bump stock or trigger crank within the Commonwealth of Massachusetts you should contact your local police department or the Massachusetts State Police to get details about how to transfer custody of the prohibited item to the police for destruction."
Note the distinct absence of any mention of other options, such as bringing them out of state.
Clearly intentional, by their way of thinking, moving it out of state doesn't remedy the problem that these devices shouldn't
be in anyone's hands for any reason, regardless of what state they live in.