If the team is not in contention, I can understand moving a guy like Betts to replenish the farm. If the team is contending, as they should during this window, then IMO, it would not make any sense to move him.
I understand that the luxury tax limits are not hard caps. Ownership can spend as much as they want, but they have shown that they do have a self-enforced limit, which is somewhere near the luxury tax amount. And rightly so. By spending that amount, they are throwing their weight around.
Every fan has the right to expect them to spend more or to spend without limit if a need arises. I think it's an unreasonable expectation, but they have that right.