Swifties are really believing Taylor sings in that song. Watch them find a way to credit Taylor for the success of the song and use it against the haters.
It starts mixing Rihanna and Taylor's oooh's together. The final and longest oooh in that timeframe sounds nothing like Rihanna - it's definitely Taylor.
Didn't Taylor already admit to co-writing the song, though? I swear I remember her tweeting something or posting something on Instagram about her co-writing a song with Calvin Harris. This was like a couple of days or a week before This Is What You Came For came out.
This makes a lot of sense actually. She was promoting it heavily which she didn't do with Pray To God (even though she's friends with HAIM) or any of his other singles.
Plus you can kind of tell by listening. The chorus melodies sound like something she structured.