Wait, this makes no sense.
Forgive me if I may be wrong (and let me preface by once again pointing out that I don't know dick about them fancy computer doodads), but considering Wii-U has double the amount of RAM than the PS360, shouldn't the CPU also be more powerful in order to take advantage of all that extra RAM?
Did you read the last two paragraphs in those articles? He says right at the end that the reason WiiUs CPU seems slow is because it's new and they're not getting the most out of it yet. I'm sure there's a thread on this forum totally ignoring those paragraphs though..
But to answer your question, no you don't need more CPU power to use more RAM.