There is no reason for Cyborg Santos to not try to make 135.
145lb is dead in Strikeforce. Staying at that weight would leave her with no one to fight. If she did convince Rousey to fight at a Catchweight, there would be no title on the line. So, if she won she would still be a fighter without a division. If Zuffa releases her, where is she going to go? Invicta is great, but it is new, not stable yet, and probably not able to afford her. Bellator is stable, and may have the cash, but she would still be looking at very few credible fighters to challange her, without credible opponents her drawing power will decrease, and her exposure will be reduced as well. Fighting at 135lbs would be a win/win for her. She would make a ton of money (win or lose). If she won, she would prove that she is a great fighter without roid enhancement,and she would be a champion again. If she lost, it would be after a long lay off, and she would have the excuse of cutting weight. She would still make a lot of money, and even if she lost there would still be plenty of fighters in Strikeforce for her to matchup with like Tate and Kaufman. The best future for Cyborg is 135.