I agree with one of the mods. Scorpion and Subzero are way higher than Noob, Smoke, Rain popularity wise. Only these 2 are staple.
Then we have Johnny, Sonya, Jax, Kang, Kung, Kitana, Mileena, Raiden and Kano who are not only popular but also somewhat play a role in the plot (yes Kano is a rival to Sonya and Jax).
Rain, noob and smoke have been doing jack-sh*t since UMK3. I do think their design and gameplay are cool but many other players can say Cassie, Kotal, Dvorah are just as cool.
Rain, noob, smoke have a fair chance just as new comers and returning 3D fighters, they are not that unique, not that iconic, not that important to the plot. Most people saying they are important are ones who stuck in the past and whine on a forum. Casual players don’t go to forum, that’s why you don’t see how much they love new comers.
I have played MK since MK4 era, and I think MK11 roster is a perfect balance. I do hope Takeda, Rain, Mileena and Fujin to make it, but so far so good.