They already did this with Legacies. It was pretty much Buffy for todays preteens. Even had some of the same storylines. Wasn't too bad really. Wipes out the need for a Buffy reboot at all - and had some Harry Potter in too which appeals to most in this fandom.
I know nothing of the networks, but I see the anti CW snobbery a lot. Seems bizarre to me, but I am a long, long way away from that space of tv choice luxury. We only just got more than 4 channels in my country this millenium.