First, the information is not yet obsolete, since Esellerate still works until September 30th, including the users support site to retrieve their old orders.
From your own point of view, meaning what your are supposed to DO to activate a scenery as an user, nothing has really changed: you still press the "Register Serial" button, type some Serial Number, and wait for a confirmation so, what difference does it make, if the software is connecting to Esellerate (and it still does, until the end of September ) or Soraco, considering even an Esellerate Serial Number WORKS on Soraco servers as well ?
The only differences are the Buy procedures, which shows outdated screenshots, but still, users will still have to press the SAME button as before ( "Buy on Web" in the Addon Manager ), it's just a different webpage will show, which still looks like a very standard shopping cart website, like countless of others so, again, what difference does it make, if the web page looks different, considering the sequence of operation the USER is supposed to DO it's the same ? We could have change the theme on the old Esellerate website, would that require an updated manual too ?
The only thing really different, is the offline activation, which incidentally wasn't even there in the old installation guide, even if Esellerate had that feature as well.