Why cant Morgana get recoloured particles?

Yesterday, according to Reddit, Riot August told his stream that Exiled Morgana won't be getting a different vfx because it's a low price skin. My question is if Riot had the tech to recolour Ashe's particles for all her old skins, why can't they do that for Morg's?

What's stopping them from simply putting red and gold onto the pre-existing particles, especially when it's been shown that skins price does not determine its quality in reworks, as Infernal Akali got more changes than All-Star Akali and Shadow Evelynn got more changes than Safecracker, and we know from chroma's and Ashes skins that Riots more than capable of changing the particles textures.