...You mean Toon Sheik. Tetra was never once confirmed. People tried to make it sound like it was her because "lol, I can't believe an OC is playable". If he meant Tetra as the file name, he would've said so. Also, Toon Link is literally a name created for Smash too. Giga Bowser is also a Smash OC. It's not hard to believe his first thought was clones of Zelda and Sheik specifically.
Chorus Kids weren't literally confirmed either, to clarify. We only know it's a RH character, and it's Gematsu that leads us to believe it's specifically Chorus Kids. Also, you are mistaking scrapped for "considered but discarded". Toon Sheik, Dixie Kong, and Toon Zelda are the only ones who had any data other than Chrom and what appears to be pieces of a Rhythm Heaven character.
Though as noted above, technically Plusle & Minun, but Pra_Mai isn't as blatant as the other Forbidden 6 characters, who are straight out clarified by name. We also don't know if any literal work beyond a file name was done for the characters who weren't playable in Smash but Dixie.
Overall, among everything, we can literally confirm Dixie Kong is scrapped. The rest is far more questionable, but being in the data, you could call some of them scrapped too; Toon Zelda, Toon Sheik, a Rhythm Heaven character(most likely Chorus Kids), someone who means Pra_Mai(likely Plusle & Minun. This would fit too, being replacements for Pichu as is, due to as similar bodyshape. Toon Link did use Young Link's model to help create him, and they share the same role. It's implied Toon Link replaced Young Link in Brawl too).