PDP is releasing a Wired Legacy Adapter, which will let you use your e-kit with Rock Band 4!

You'll go from your drums -> Midi PRO-Adapter -> PDP Wired Legacy Adapter -> Xbox One.

There is one on Amazon now if anyone wants it. It's 50 bucks. https://www.amazon.com/dp/B00409SOD2/ref=cm_sw_r_cp_apa_fabc_P35JG9SJ1WWJ1YWHMW50

This might be what you're looking for, not sure about the compatibility on guitar hero games though.