Do it! Ive def been there my friend, and i can tell you that it feels good as hell. If you find comfort in “act like youve been there before” then more power to you, but i also think that people should be free to be excited about things! Enthusiasm is great for your self esteem, or at least it is for me!
Im curious why your conception of a warlock must be able to be confused with a wizard or sorcerer from an outside perspective. That has never been an aspect of warlocks in 5e that I valued, or something I particularly wanted to emphasize.
To me, a warlock character could be made using any number of classes present in pf2, including the aforementioned sorcerer, wizard and witch, but also the psychic or oracle. The fantasy of having a patron is not something that must be expressed mechanically IMO, because it ultimately boils down to “you have a connection with this powerful NPC and you need to consider their wants/needs/demands or else there may be consequenses”