Solo was in trouble before anyone ever had a chance to boycott it. The fact that the original directors were fired and Ron Howard brought in to salvage what they could, requiring reshoots and blowing up the budget, shows that. And despite that, the movie still took in 400 million dollars and was the #11 movie of the year. A year, by the way, where Disney had the #1, #2, and #3 movies.
Disney paid a lot for the Star Wars franchise, and i've read articles claiming that they could have gotten a better return on investment putting the money elsewhere.
I think the claim was that each movie had to make over a billion dollars to be a financial success, and 400 million was no where near what they needed to make to recoup their investment in the franchise.
Obviously Disney thought something was wrong, because they've put a hold on other productions, and they were sniffing up JJ Abrams tree.