Eh? Broccoli never kills Nanami off tho? She literally just got some new merchs too, like the NuiStars, together with Tomo-chan. But they're becoming more and more closer to real idols now so it's just natural for Broccoli to focus on them from idol perspective. But we know Nanami will always be there supporting their back, like when they showed her watching the boys performance from the backstage in the MLK credit song.
Yeah, Broccoli has never put Haruka off. She still has merch coming out, not to mention that she's credited in Otoya's Birthday Song as the composer. Besides when it comes to idol/music franchises, they mainly focus on the idols/bands however that doesn't mean that they just completely forget about the producers/composers/ARs/etc. They do exactly what we do: support them no matter where they stand
They never "K1lled" haruka she's always there with them, just as we are. It is just that from shining live on we are not Harukas but ourselves. We can stand by their sides being their fans and inserting ouselves in the story. Haruka is still there, i hope we get some of her POV in the anime tho. She's the mc of games and anime, they're focusing on the boys as idols now