You have to wonder what is really in it for the buyer. I imagine just a means to get the list of forum member email addresses for marketing purposes and to throw more ads on the front page. RS hasn’t been a news worthy site since Curto left almost a decade ago. The change in RS now or tomorrow is insignificant nowadays.
The value of user data is something that tends to go by most people without much regard, but there can be significant value there in large communities. In the case of RS, I don't know if that's even worth it because I get the sense that their user data might largely be dated. But I would not put it past the new owners to sell the user data to whomever.