i'm not a fan of this particular endeavour. the brand is going to suffer as a result. ANYTHING with mediatek inside will not get its OS upgraded to another major version of android. mediatek is fickle like my wife during her period. one month they behave like a completely closed source company, only releasing binary version of android for manufacturers, the next month they sponsor XDA Devcon 14 and release source code for Android One devices, a month after that they once again completely ignore GPL.
in my experience, each chipset gets around 3 months of small updates, the few that got upgraded to lollipop were the ones released with kitkat when lollipop was already out and would otherwise have been unsellable. (and that's android 5.0 not 5.1)
apart from elephone and android one devices, there has never been a cyanogenmod for a mediatek device because there's simply no source to use. i fart in mediatek's general direction and shed a tear for commodore.