Its not a transfer, Its a clone Of progress to other platforms, so theres no real loss to the console user at all for doing so...
They have yet to announce Which platform the Free Horizons client offer use will be for, as announced on the stream you will not have to buy Horizons on PC they announced on stream A free copy will be offered for horizons for PC...
I Expect the free Client stated in stream will only be for Fdev direct access... not steam or epic you will just change the account that logs in to the Fdev Launcher for those PC stores versions but you have to pay for them...
The not moving ARX accross Is the keep Microsoft happy clause as is the not erase the old account, this will have been what the legal team worked out with Microsoft... As no accounts are going to be removed, you are still able under pressure from other players to stay on console and be active still...
This legal work is going to allow avoiding breaking there legal store licensing deals...
From what is posted and the live stream console users are getting a Free horizons PC version of the game and Restricted progress copy to PC account, There has been Nothing Shown So far as a reason not to do this copying.
A part from the fuss of picking a new name for the new Fdev account on PC if its in use allready there are no negatives unless its confirmed that you cant get a free "steam" or "Epic store" PC version if you wanted one...