the ratings are fine for the cw.
i mean it did way better than crazy ex girlfriend's premier and despite crazy ex girlfriend averaging only around 500k viewers a week it still got picked up for another season.
it's not super far off from jane the virgin's premier... either way i doubt the show is super expensive to make, so giving the reception there isn't much need to worry about right now.
Part of me wonders if Rachel Bloom's Golden Globe win was a significant piece of Crazy Ex-Girlfriend's renewal. But you're right, Riverdale had an average premiere rating. Being all over global Netflix will help!