No. Since 'Yiffy' isn't part of the mainstream Lion King story, it's not likely to be a popular story in general. Most people are familiar with the original Lion King plot and characters.
Probably not. The Lion King has a very well - established and popular story with characters like Simba, Mufasa, Scar, etc. Yiffy, being an unknown addition (not from the original), is not likely to be part of a widely - known story. It might only be popular within a very small community that creates or follows this specific 'Yiffy' - related adaptation.
I don't think so. The Lion King has a global fan base that loves the classic story. While there could be some niche fan - made stories with new characters like Yiffy, they don't reach the level of popularity of the original Lion King story. The original story's themes, music, and characters are what made it so iconic, and a new and unrecognized character like Yiffy doesn't have the same broad appeal.