Blow would have happened sooner than later, and with or without Rihanna. After B'Day and 4, Blow was just the logical next step as part of her growth. Just like Grown Woman and Standing On The Sun and even currently Hold Up were a logical step after her doing songs like End Of Time and Countdown. And just how she evolved from songs like Ring The Alarm and I Care to ultimately Don't Hurt Yourself. A song like ***Flawless also would have happened, especially with the fact she has been a feminist for ages and that it basically a logical evolution of songs like Back Up and Upgrade U to an even more hard hitting song.
I just don't get how people can be so delusional and try to reach so much