At least from the surface, that's just really poor event management. Sometimes "stuff" does indeed happen but, in general, whoever was choosing talks should have been aware of potential landmines. Disinviting people has a pretty high bar if it's from a change of strategy on my end.
To be honest I was aware they were reluctant to talk app-layer interfaces. They were hoping to 'capture' InfiniBand similar to how video was captured with DirectX.
Once I submit and paper and was accepted, I assumed they'd relented. But day one of conference I was gone from the schedule - the session time slot was blank.
