This is strange.
In all the years I have worked with Regent this has never happened in this manner. ONCE I was called and asked if any people in my group might consider changing to another date. Regent had a wonderful offer ready. They asked if I could see if someone would be willing to volunteer to take the offer. They got a cruise twice as long with a big upgrade and were delighted with the offer. I knew just who to call. They had to be the type of people that were flexible with time and travel plans and had Regent air so there was no difficulty with flights.
Anyone in this mans situation is not in that position where vacations are flexible. It just does not sound right - there must be something missing here. Why him? With a cabin assigned and without first seeing if there was someone in a group that might take the offer or calling active TA's to see if they had someone that would voluntarily take the offer.
This is not something that is a normal situation with Regent and particularly to just pick someone like this and say "you are bumped". I have seen this with Oceania a lot in fact it truly is a problem, but not with Regent.
Be interesting to see what develops here. It just seems so strange to me.