FWIW Henry also did that after winning a world series, when is the last time the O's won one? Don't get me wrong, I'd rather have their 26 man any day of the week right now.
Also, at the time Mookie Betts had one year of team control left, Henderson has 5. Also, at the time of the trade MLB had him as a top 50 prospect in all of baseball. I think most rational fans, of any team, aside from being justly angry at trading away a star player would be happy with a return of a top 50 prospect for one year of team control in a guy.
The next team who trades away a star on the cusp of FA who won't resign there and gets a top 50 guy in return might end up trading for a future MVP. You just don't know. Predicting human beings futures is hard, although I heard some ladies will look into a crystal ball and tell you the future if you pay them money. Might be a scam....not sure.