TPOT is the season with the least unused or unseen content currently. This is because the source files are not out yet, but for now, this article will list the currently available unused or unseen content of TPOT.
Please note that for all intents and purposes, none of the information documented is considered to be canon with the rest of the series.
While Liy still appears in TPOT inside the EXIT, she was originally going to compete in TPOT. Originally, BFB 16 was going to have her escape the EXIT with Loser and Spongy. While the two did escape the EXIT and stay in BFB, Liy would have escaped the EXIT and compete in TPOT. When this was scrapped, the crew had to make a new plan for 42 contestants, as Liy going to TPOT would mean 41 contestants from BFDI-BFB. This would also mean Price Tag wouldn't compete.
"You Know Those Buttons Don't Do Anything, Right?"
In a Patreon post made by jacknjellify, recommended characters and name tags from February 2020 to March 2020 were going to appear in TPOT 1. While the relevant recommended characters appeared in TPOT 1, the recommended characters and name tags didn't. This is possibly because of time constraints or the crew forgetting about the recommended characters and focusing on animating the relevant recommended characters.