Joey wrote:I'm sure i've seen this in other codexes as well. I think you're reading too much into this.
Agree with that. Personally I'd guess it's a background/flavour difference. Lots of weapons that are actually powered are described as power weapons, lots of models that are just really strong or whatnot are described as having attacks that ignore armour saves. It's certainly not some super-subtle groundwork for a rules change (after all such a radical change would require written amendments to most codexes anyway)