Technically yes and technically no. Lemme explain by saying in order to get monetary value, Preggopixels had to remove any "copywritten" stuff that was in the game. Hence why currently, many of the artwork looks similar.
If you're looking at in particular Valorie or Sauna, the very detailed versions were copywritten, and thus couldn't be used. Thus a new artform has taken place in 0.4
Also, this is a bit game, so similarities of sprites are not to be surprised about due to limitations of the engine and pixel sizes.