Ahh, the memories
I recall being at a Microsoft training session where the head of one of the games units told how he was there when they acquired a popular game--the entire company, staff and all.
At the end of the first year he had the existing MS programmers present awards for the best achievements for the division. All of the awards went to the new people.
I never did hear what happened over the longer term. Probably most of the new people became newer people elsewhere.