SCE did have direct control of SOE prior to the sell-off, so this news shouldn't be dismissed as irrelevant because SOE weren't as focused on PS4 as other first party developers.
From a business perspective the sell-off obviously makes sense for Sony.
SOE had the data leak in 2011 which was bad press for Sony and maybe they didn't or couldn't foresee making it secure enough to stop this happening again.
The Playstation fan base seem to prefer games that aren't online unlike XBox fans. (How many times have we seen Playstation fans saying they weren't interested if a game was online only?) XBox would seem a better fit for online.
Sony does need money. Maybe this is part of why they delayed their financials. At least we can see they are still in a position to invest in profitable sections.
This news is a bit of a shock, but probably more relevant because it is part of the Sony gaming empire and had Sony in the title, so it sounds like PS4 is losing more than it is. It could be more damaging from a consumer confidence perspective. Anyone with a PS4, or potentially considering buying one must feel a bit more worried about the future of Playstation this morning.