I would say no, for knowledge skills and yes for contacts, simply because the character creation process is broken down into steps.
Buying skills (also knowledge skills) is on step 4 (at least in my German edition), while grabbing connections and raising attributes with karma is both on step seven.
Within the steps, I would say you are free to do things as you please (raise attributes, then buy connections), but you can't go back to step four and spend your newly raised points to buy knowledge skills. Your GM may deem otherwise, but this is how we handled it so far.