[gottago]

According to RXTV three of the Box channels "broadcast under branding licence to Bauer Media" (Kerrang! TV, Kiss TV, and Magic TV). I'd hazard a guess that the branding licence which covers these channels may be due for renewal sometime this year. No point in continuing to pay to use these brand names if revenue from those channels is falling and Channel 4 is looking to cut costs.

Good point, it would also be a lot harder to sell the channels if they don't come with the brands, or would cost a lot to keep the brands so make even more sense that they would close them fully.