I don't think they will, but even if they did I kind of suspect the apps will still shutdown, they all announced their shutdown at once, I am sure they discussed amongst each other and reached a line in the sand with reddit. If I got that sort of treatment, even if they backed down I'd never trust them again, I'd never want to work with them again and I don't see how that sort of situation is tenable. So they could completely abandon the changes and still have achieved the result they want. However, at this point they've already vilified themselves to those who will ever care, so there's no reason to back down at all.