The problem with this little scenario is that while Rubio can release the delegates pledged to him, he cannot direct them where to go; they are not his to control. They are pledged to him for the first or first and second ballot and that’s it. They are not his little robots. Nor are they Trump’s.
“They are pledged to him for the first or first and second ballot and that’s it.”
According to FL rules, delegates are pledged through 3 ballots, not 1 or 2.