With the duel threat of Savitar and Doctor Alchemy on tap along with Flashpoint… the fear is that the show will get even darker.
Executive producer Aaron Helbing told TVline that's not the case:
Zoom, in general, was dark It even got darker than we probably anticipated So we're making a conscious effort to go back more[...]
Savitar Archives
After having the big bad for season one be Reverse-Flash and then for season two it was Zoom… fans have questioned the logic of bringing Savitar in as a big season three villain.
IGN asked executive producer Todd Helbing that exact question Why another speedster? Is it more interesting when Barry has to go up against[...]