Or more likely, Bilsy would have been at the end of Jungle and Tweedle somewhere in Psych.
Nope. They were coded, usable, decided against, cut, and replaced. It's not like we would have gotten the blade gun and the electroblaster at the same time... for one thing, there are only so many number keys on the keyboard.

Meh. For any given "scrapped" feature, including the many not listed on that page, there are going to be a number of overlapping reasons it ultimately didn't make the cut, ranging from fun factor to programming difficulty to whether anyone ever thought about it. (I imagine the Spaz blaster powerup is in the third category. And probably "Max Weapon" wasn't so much scrapped as someone randomly wrote it down as an idea one day and then nobody ever looked at it again.) But is that proof that JJ2 somehow vastly outstrips other games in how much revision was done during development, or just proof that JJ2 is bad at hiding it? (And in some cases, hiding it against JCS, JSD, and JJ2+, tools that most other games don't have sitting around to hunt for unfinished ideas with.)

Some content definitely looks like casualties of lack of time, sure. The secret levels come to mind. But I don't want to fault Epic for making any revisions during development at all, because that's how making games is supposed to work. The alternate Beach background, the Tubelectric spikes... they were used, considered, and rejected. That's normal.

The unfinished JJ1 tilesets thing on that page pretty transparently doesn't belong there. That's JJ1 cutting room floor stuff, not JJ2--they're just there because they needed .anm files to test MLLE's code with, and then nobody ever bothered to remove those files from the folder.