As it stands all we really know about advanced cancel is that you can cancel DM to SDM, but we don't currently know if DM to DM is ok. I haven't seen any info saying that CDMs can be canceled into, but I see no reason to believe that isn't the case.
What makes me concerned is how they'll treat grapplers with these cancels. We've seen that the advanced cancel does not automatically equate an extended combo as Iori's SDM whiffed. Will grapplers like Goro or Clark be able to advanced cancel to whatever their second supers may be, or will it whiff like Iori's? If it does whiff does that make them more likely to be used primarily as point/battery characters?
I apologize for typing out my train of thought, but lastly I'd like to mention that although Iori missed with his SDM in that instance it does not make that particular cancel useless (not that anyone said it). I haven't seen that super hit or be blocked, so I don't even know it can be blocked (it probably can) but if done in the corner it could be used to pressure or possibly guard break an opponent. Further it may be that you can cancel it earlier and extend his combo if he recovers fast enough, then if it was done in the corner it'll hit later setting up either juggles or even more ground combos. But of course this is all speculation so my ramblings should be taken with a grain of salt.