Making a UC TV series doesn't make sense. There's a serious disconnect with the core audience. UC fans are generally adults in their late 20s to early 40s. These are not people who generally care to follow year long series with average production values and then buy blu-rays for the entire series monthly as the discs are released. instead the audience are the type who are more discerning when it comes to purchases, preferring quality over quantity. They are the main market for MG models and PG models, and quality OVAs and theatrical movies.
By making a UC TV series, Sunrise stands to put themselves in another lose-lose position where the younger audience who watch TV and the people who tend to buy TV anime aren't interested because it is before their time or not appealing enough for their tastes, and the UC fans who would spent a lot of money on stuff like MG kits and Unicorn aren't interested because the format is wrong.
By making a UC TV series, Sunrise stands to put themselves in another lose-lose position where the younger audience who watch TV and the people who tend to buy TV anime aren't interested because it is before their time or not appealing enough for their tastes, and the UC fans who would spent a lot of money on stuff like MG kits and Unicorn aren't interested because the format is wrong.