I think all companies should do the same in any acquisition, and especially in ones such as this where you are basically buying the user base and not necessarily the technology/people.
Yes, but Google should be careful not to alienate the people that end up staying. It is necessary for the success of their company that they maintain the Google culture, but the danger is that they seem like a callous giant company who doesn't care about the new people.
It's sad but unfortunately it's reality in most cases.