AES-256 Shift-Rows Offsets
Actually, the document talks about Rijndael, not AES.

Aren't Rijndael and AES that same?  Well, not precisely; Rijndael is specified with a set of parameters that AES does not support; how example, how it works with different block sizes.  AES is defined only with a block size of 128; Rijndael supports a set of different block sizes.

That is where your confusing is coming from; the varient shift-rows are used if you have a block size of 256 bits; since AES never has a block size of 256, those shift rows are never used.