Regardless of which one ends up being a bigger hit, the true tea is found in the original post. Take a glance over WHYB's writing and production credits, and please note who's missing (and who therefore deserves little congratulations about why the song is hit worthy in the first place).
If Beyonce brings it with End Of Time it will be an instant number 1. Rihanna has too many songs on radio. Where Have You Been will just mesh in with everything.
I see WHYB smashing but EOT not so much. Sure it's a great song but it lacks that extra hook factor that would make it smash. BTINH was almost there but still felt short with the perfect hook. If BTINH failed to break into top 10, than I don't think EOT will reach top 10 either. Best I can see it is top 20