Does Victor's advice to Walton change by the end of the novel?

Well, let's see:

The story begins when Walton rescues Victor, tells him about the purpose of the expedition, and Victor tells Walton about manufacturing a monster in order to curb Walton's grandiose ideals.

The story ends with Victor berating Walton's crew for quitting the expedition out of fear for their lives.

Yes, the advice seems to have changed. In the telling, perhaps Victor became enamored with himself all over again through Walton's adoration. Maybe, despite his own failure, the warning he gave Walton did not read as, "Don't go through with this harebrained expedition to the North Pole, my friend," but as, "Do not do this looking greatness, but seek truth and honor for yourself." Victor's purpose in life was such a selfish one that, rather than curbing Walton's plans completely, maybe he just wanted to impose a bit of realism and self-awareness on them. They are big plans that have the potential to change the world and contribute to human knowledge - that is a worthy undertaking. To do it simply because a person wants to be well-known, never forgotten, makes the effort petty and silly. This way, the apparent change in Victor's message to Walton would make more sense.