You're not wrong, imo. Try some null tests between the original source and the various ableton warp modes even at the same BPM. There's really quite a difference, re-pitch is neutral at the same BPM.

I'm not expecting them to null at all, but the difference left over is pretty unpleasant in a lot of cases, pretty nasty in some cases, some cases everyone was told were neutral at one point..which explains a lot about the old reputation of it's engine.

All you need to do is drag a fader plug in and invert the phase, making sure the volumes are exactly the same and no live unsynced or random modulation is present.

More to the point, the way Ableton is at default settings in samplers and drum racks, you're going to have a very different set of results simply, resampling > slice to drum rack. It can be changed to do it with no deviation whatsoever from the original sound, but why it's not set up to do that is a mystery, the main advantage of digital is meant to be no degradation...