You're right. But to be honest the one article on eurogamer from early 2013 is the only one that mentions a PC/M+K specific UI IIRC and it doesn't feature a direct quote on the topic. We don't know whether CDPR said "There will be a PC specific UI" or whether theay said "We strongly considering making a PC specific UI" to the eurogamer journalist...
@orblivion
Well, you can play Witcher 2 on PC with a controller as well. It's obvious that CDPR didn't have the time, money or will to make two seperate UIs for controller input and M/K input. Imo no good UI designer would implement a ring menu for a M/K game. If you use a keyboard you have lots of hotkeys to directly command for example spells. That's why PC RPGs with M/K input usually offer a hotbar for the keys 1-10. Controllers don't have that many buttons. To be able to quickly access spells in combat UI designers invented the ring menu which uses the input methods of a controller (one hotkey for the menu and navigation with the sticks). On PC with M/K that's kind of clunky and more inconvenient than necessary imo. Same is for example true for list inventories. They are the best option if you play with a controller but clunky and inconvenient if you use a mouse/keyboard configuration...
The question is if there will be a M/K specific UI or not. PC is probably a mistakable term here.