My understanding is that another bank will take over the account and honor accumulated miles

Probably keep card to use anniversary companion ticket and then open a new card offering jumbo free miles

Always keep AMX which we have forever

we are fortunate that we have several airline options to fly to SXM and even optional airports if we wished to drive to JFK for a direct flight although a bit of an inconvenience

a four hour direct flight is a blessing compared to a long all day travel starting at 2:00 AM