There is a lot of incorrect information in that list, but the idea behind the topic is right.
64
Bowser, Mewtwo, Dedede, and Wolf were all planned, and they all made it into Melee and Brawl. Those are the only characters who were planned for the first Smash Bros. that didn't make it in - there were no plans for Peach, Pit, Meowth or whoever else.
Melee
Sakurai wasn't sure if he could get permission to use Marth from Intelligent Systems, so he had some concepts for Dedede drawn up. In a way, Dedede was replaced by both Marth and the six clones (since Sakurai opted to use the extra development time to implement them rather than Dedede).
Wario, Leaf (from Fire Emblem), and Wolf were all considered as clones, but they were all dropped for various reasons and later were used in Brawl (although Leaf was in Melee as a costume).
Sakurai also came up with the gimmick behind Pokemon Trainer during Melee's development, although the character would have been made up of the G/S/C starters instead of the R/B/Y ones (since he originally envisioned the character as a second-gen representative). He got cut because it would have taken a lot of work to make the character and everyone felt that that one character wouldn't be the best use of resources.
And then there's the thing where Lucas was going to replace Ness and take his moveset that everyone already knows.
I don't even know where you got the idea that Scizor was planned; I've never heard that before. Did you make it up just now?
Like I said... Speculation.
You're also forgetting the fact that even characters that work as doubles have separate data/files. (See: Ice Climbers).
We aren't sure what that was going to be.
"pra_mai" can't refer to anything but Plusle and Minun. It's like if someone cracked open the first SSB and found references to "fushigi" or something. And it doesn't make sense to say that they were only in the game as a test for some other character, because why would they specifically be in the game as a test and not Mewtwo, Roy, or Dr. Mario? I don't think it's a coincidence that if you were to put all of the cut Brawl characters into the game, you would pretty much have all of Melee's roster.