It's a terrible article done by CVG. The list that was halved is the EU list. All territories outside of EU were not revised at all.

To make matters worse, they then posted the revised EU list and compared it to the "original list", which makes it look like ~75% of the developers were later removed.

So we have misleading title and article content from CVG.

Why Sony Lies ?!

Just to Fear Microsoft

"Many of the studios removed from the original list, such as Mojang, 17-Bit and Vlambeer, haven't outright ruled out supporting Sony's next console, and have simply stated they either have nothing currently in development for the console, or haven't decided on anything yet.
There is a possibility that some supporting studios may have wanted their names removed to prevent their projects being announced informally or prematurely".

this kinda sums up possible reasons why...

Here is a better informed article by Joystiq.

505 games have also came out and stated they while they have been removed on the revised list, they are in fact planning to publish games on PS4. So now it's 53 to 29.

http://www.joystiq.com/2013/02/25/sony-completely-revises-list-of-ps4-eu-studios-down-from-53-to/

well if you want to look good you have to show stuff even if that stuff might not come later on

this is nothing new with Sony

hmm

good find, Euphoria

Nevermind.

Well this is only Europe, but could other regions follow suit?

Still a very poor oversight, though.

The list that got revised is the European list. We'll see if the other lists get revised, but I'm thinking this might be limited to that region. Still messed up though. They need to not do this kind of thing.

No, this was pretty obviously a mistake.  Someone put up the wrong list.  Some of the developers they failed to include are better than the ones that shouldn't have been there.