I don’t believe it really matters whether it was a jammed thumb, or some sort of a sprained ligament/tendon that doctors cleaned up surgically for pain management.
My personal opinion is Hoover did have surgery, and for whatever reason, the team/agent does not want it reported. JD Andress is an excellent reporter, and he had 3 sources that he held to be reliable. All 3 sources definitively told JD that Hoover had surgery.
In addition, the brace/wrap also looks like post surgery, as the back of his hand from the middle finger to thumb appears to have been shaved. Just an opinion.
In the end, the only thing that matters is when Hoover is cradling the ball, can he apply whatever thumb pressure he needs without an intolerable amount of pain. As long as the level of pain isn’t making him adjust; then he should be good.