The media is already reporting social media backlash to the trailer. https://www.koreaboo.com/news/iu-byun-woo-seoks-k-drama-trailer-hit-scathing-criticism/
it will be a ratings and buzz hit regardless imo. plus we can't judge from a 40 second teaser; it could just be a weird cut
it's on netflix but they're not promoting it as it's not their original drama and they also have no exclusive…
oh maybe because it's not exclusive then, cuz netflix usually posts atleast the teasers/previews on their sns handles even for non originals. see the recent pro bono for instance. it's available on Viki as well in my region, so it being non exclusive might be the reason for the zero promo