Hey y'all, I have a 2011 American Deluxe Strat.

I noticed that the low E had a much lower output on the neck pickup, regardless of height.

I took a string and tapped each polepiece and found that the low E had no magnetic pull; upon testing the other pickups I found that the high E on the middle pickup had no pull either.

Is this normal for alnico II and alnico III pickups? The alnico V in the bridge has equal pull on each polepiece.

It's not normal, for any type of pole piece or magnet or pickup that I am aware of.

Demagnetized pole pieces are just weaker, they will still have plenty of pull. At least "demagnetized" in the sense that is usually used for pickups, i.e. degaussed for a lower output. A broken magnet could theoretically do this, though it would still have a tiny bit of pull. See if a paper clip or something similar will stick to it.

I wonder if there was a bad batch of pole piece magnets that went into your pickups. I'd email Fender and see what they say.

Manufacturers play around with things to get different sounds and features (noise canceling, usually) but I can't think of a legitimate reason to simply not have any pull on one of the pole pieces. I think this is an error in manufacturing.