I'm not convinced on this. A part of the problem with old Devourer (and the still older Feral Flare, and the still older Madred's Bloodrazor) was that the mix of heavy magic damage with heavy physical damage made it excessively hard to itemize against a champion doing well. Master Yi, for example, ended up doing huge physical damage, magic damage, and true damage, which is a nightmare for a defending team.
I think keeping the damage physical makes the item's balance far easier to tune, as most of the users deal heavy physical damage. If you have an all AD team, I think that's something you should have fixed in champion select, and your jungle item choices doesn't have to be designed to fill in a gap caused by a poor pick/ban phase.