The commonwealth option got fewer votes than statehood in the last referendum, so it's clear that Puerto Rico doesn't support it.
Nothing is clear until the votes are cast this time, not last time. Not giving voters the option to keep the status quo seems just wrong, to me. No change should be an option.
The reason it was added back in is because the GOP Congress and Trump WH do not want PR statehood which would require a massive bailout of the island to the tune of over $70 billion. Even if it did pass with 50+%, Congress would still not vote on it due to the debt issue. My guess is that if statehood does get 50+ in the ref, the only way PR becomes a state is if a Dem House takes it up starting in 2019 if they take it back. The Senate will still be Rep so it would necessitate a compromise.
Yes, because here in America, we choose to bail out the big banks, not our own territories that contain American citizens.