I think the shapeshifters comment was a worse comparison. It's one instance JMS memorably lost his shit over but it doesn't hold up at all.
DS9 has a shape-shifter as one of the main characters. He physically changes his form (Rarely!) throughout the series and his mysterious past is the key to the threat to the Alpha Quadrant.
B5 has a forgettable henchman use a shape-shifting device in one episode