This must have been a recent update or rewording. The CRL I printed off the site last summer didn't specify this, only suggested it. At least that's how I interpreted it.
"If using the Hasbro E11 toy blaster, it is modified to have the correct number of T-tracks (6 total), with a lower row of open vent holes on the magazine housing side.
This is accomplished by covering the pre-existing rows of holes with T-tracks, then grinding off the lower integrated T-track on the magazine housing side, and drilling a new row of holes in its place. "
but according to the statement above, he is correct Tommy. We'll need to fix the blaster.