My guess is Jesse McCartney was already set up to write for Archie. (thinking he was the pre-ordained winner). So when Cook won the media just extrapulated that McCartney would be writing for Cook. cook has never mentioned McCartney's name in assoctiation with himself.
Cook mentioned that he has already brain stormed with Riane Maide From OLP. He mentioned Ryan Tedder as a possibility ( only). He also, confidently said that they have chosen a few tracks already. He is Stocked! He has also mentioned that he wrote during the Idol experience. He seems to have dismissed any Analog Heart songs from being there but was not firm
He has made that drippy TOML sound better each time he sings it. I loved it the night of the finale. Don't let the Rainbow lyric get you. Clapton just wrote one with a whole lot of "Butterfly" lyrics.
I think david knows to make a Rock album but not a heavy metal or grundge. He knows what we like and he really wants to please the fans and himself.
Skinny, chubby, earing, no earring, Boots ( I love Boots, my husband only wore Frye's when we met) or sneakers, He is HOT, Sexy and Brillant. It will be great and we will love it. He is one smart Cookie

Ryan Tedder told Rolling Stone that he was glad that Cookie won and that he and Jesse were going to write some songs for/with him. It was a direct statement by one of the songwriters to a major music magazine. The media never assumed anything that was not directly stated.

Since Fuller has all but proposed marriage to Cook and is rumored to be managing him personally, I think we can disregard any talk about who was expected to win. 19 is clearly happy with what they got.

Is Fuller really managing him? I know they have not announced a producer yet

Yeah Fuller is managing him. That fact alone made me most happy

Absolutely!