Funny you would link that, because that's the exact article I re-referred to before I made my comment.
So it’s with great pride I get to announce that Insomniac will continue our involvement with the Ratchet & Clank movie while developing a game that re-imagines the original Ratchet & Clank for PS4.
As was mentioned during Sony’s press conference , the game will share the film’s vision of Ratchet’s origin story, and features updated gameplay along with completely new visuals that rival the best PS4 games on the market. Both the movie and game will be available in the first half of 2015.
re-imagine =/= remake/remaster. You could argue whether they meant what they said (I'm going to take their words literally because I assume they used the words they wanted to until proven otherwise), but, more to the point of the OP, as far as I know we haven't been shown any footage of the game or been given any other information to go on. My reading of that paragraph is that you could think of the game as a licensed movie tie-in game, not as a 'hey we remade R&C1 with new graphics in a new engine.'
What would be the difference though?
The term "remake" is vague enough that it supports both points: the HD collections versions that we are used to (restored/remastered being more appropriate), or the reimagining version we are used to from Hollywood (Criminal being a remake of Nueve Reinas)
On topic: I don't know anything about that game, but given how they handled Into the Nexus and Full Frontal Assault, I could definitely see them working on the game without much fanfare until the very week it is released...