Until Epic say they have regrets this is just opinion.
Sure, if they could now dump Gears on PS3 then from a pure business perspective that would make sense - even 3 million in sales across both titles, which would surely be likely, would deliver big chunk of easy profit.
But Gears got huge backing from MS and marketing, and I think it helped it being exclusive initially.
So I doubt Epic regret anything.
Try to be reasonable... its easier than you think...