The coaches have only said that he'll play both, not that he should be expected to start in place of Heder in the case of suspensions. WLB is thin, too, with Takitaki out.
I have been listening to the coaches and paying close attention to every practice report; if you aren't a little surprised by this, I think you're the one who hasn't been paying very good attention. We have heard nothing lately to indicate that JLD has played with the first string at ILB in a while, but he has been the #1 WLB for a while. We have also heard very little about how Heder is doing, which I think is the story here. If Heder were healthy, I think we'd be seeing him start instead of Tautu (who has generated no buzz during fall camp after generating a lot during spring).