As sociopatic and narcisistic as gotti was, i hardly think he would have liked that strategy. Taking the fall himself and letting sammy go doesnt sound like him. Especially when you factor in their strained relationship at the time and Gotti's policy regarding plea bargains. After beating the feds before i could imagine that gotti thought of himself as untouchable, and he wouldn't have given up without fighting the charges. Plus i doubt the other bosses would have liked the signal it sent to the lower level soldiers and capos. Just my thoughts.