yes, u r absoulutely right, one of the proposition of ms buying yahoo is to get on open source bandwagon because most of the startups are open source and it would be easier for all future buys for ms to integrate with yahoo apps/platform.
But this discussion is about taking care of employees's and customer's wish and aspiration - again what if key employees and customers of flickr, delicious etc.switch their loyalty just because they were not respected and considered during m&a....
sorry, but i haven't read any survey regarding whether or not yahoo's (and its subsidiary's) employees and customers are for or against the merger.