In order for me to buy in to pre-painted minis, the process would either need to be prohibitively complex (as in, pick a Force Pack and a color scheme, and the pack is 3D printed for the customer) or I would need to completely re-think how armies are raised and battles are fought (basically shifting from "Dune, but with mechs" to "Warhammer Fantasy Bretonnia, but with mechs". If the quality was good enough, I think I could probably come around to the latter, but it would still be a struggle for me and it would run counter to last few decades of fiction and sourcebooks.
Even then, the overwhelming majority of my interaction with Battletech has been via painting minis, so a major component of the soul of the game would suddenly be missing for me. Would it be a nice option if I suddenly needed a large OpFor? Maybe, but even then, it would bug the hell out of me if everyone had drastically different colors and heraldry.