The biggest Edge change is that you can reroll your enemy's dice! O_O
Yes...
"Realism" is not really a useful term for a game with technomancer elves, but I think there are genuine concerns at work. Most of these ideas float around in game design circles, but I'm making up my own labels for them.
Games can be "immersive" or "narrativist" (let's say). An immersive game is one in which the player and the character make decisions for essentially the same reasons. The character dives behind cover for protection from bullets; the player has them dive behind cover to get the bonus to armour. Essentially the same reason. A narrativist game is one in which the player makes decisions for completely different reasons from the character. The character loses his temper because the ork insulted his mother. The player has the character lose his temper to get a Fate point that she can use later.
Shadowrun has been immersive so far, but the new Edge system sounds like it might be narrativist. It might not be; hiding behind cover because you get Edge is not that different from doing it to get an armour bonus.
A separate distinction is that games can be "simulationist" or "gamist". In a simulationist game, bonuses and penalties all have sensible origins within the fiction. You get a bonus to armour because you are hiding behind a concrete wall, for example. In a gamist game, the bonuses and penalties come from the game mechanics, and might have no foundation in the fiction. You get a bonus to armour because you spent the Fate point you earned by having the character lose his temper.
Shadowrun has been broadly simulationist so far, but the new Edge system sounds rather gamist. "I successfully hacked this system because I hid behind a wall earlier." The implementation details really matter here, though, and I, at least, don't know those yet.
Then there is "realism", which means that the game mechanics model the way the fiction is supposed to work. (We had a great deal of trouble in Ars Magica trying to create realistic magic resistance, which in one sense is absurd, but in another makes perfect sense — the mechanics should reflect the way the fiction describes it.) The concerns about the Knowledge skills and Armor are about realism in this sense; the concern that the mechanics won't reflect the fiction.
If Sixth World makes Shadowrun narrativist and gamist, I think it will alienate a lot of existing players, but I don't think it is at all clear that it does. If nothing else, the Edge mechanic does not sound as though it dominates everything, and the attributes and skills are still immersive-simulationist.