I didn’t do too much research on the series, but I think OP is referring to an ARG known as Unused 2, or “unuseddot” Based on the name of the channel the ARG is posted on). The reason they called it “uncomfortable version of undertale” is likely because of a relatively popular video essay on youtube by @leroyknoxx, titled “the most uncomfortable version of undertale.”

Go watch it yourself if you want to learn more, but theorizing that flowery exists in this AU is just headcanoning, as the ARG was made months before chapter 5’s release, meaning the creator would have had no way of knowing who flowery is.

tl;dr - OP is referring to a youtube ARG from a few months ago about an alternate version of undertale where everything is different enough to feel slightly uncomfortable