Back then we reached out to both Sony and Ubisoft asking for a clarification, but we didn’t receive a direct response. The actual answer came today, as the house of PlayStation quietly removed the mention from the website, replacing the banner with another that still claims the PS4 version to have the “best graphics on any console” but without any explicit indication or resolution and frame rate.
At the bottom of the post you can see the original banner (above) and the new one (below). Unless we assume that someone at Sony decided that it wasn’t classy to boast too much, it’s very unlikely that the game will run at the previously mentioned resolution and frame rate, even if the new banner still seems to indicate an edge over the competition.
For the moment there’s no indication of what the final resolution and frame rate will be, and we’ll keep you posted as soon as we learn any relevant information.
Update: a preview posted this morning mentions that the game does generally run at 1080p, 60 frames per second adding a further layer to this mystery.