Once upon a time, we had or were going to have an option that would automatically generate a tag set for your prompt meme or challenge. I don't remember this at all, but I know this because we recently removed the help documentation for it: https://github.com/otwcode/otwarchive/pull/2709/files#diff-a276da14bbe6464df24ab3d87ce29064
Anyway, we don't have that option now, so it seems like a good idea to remove the few lines of code that appear to be related to it.
How to test:
We can either trust the automated tests or manually make sure gift exchanges and prompt memes with tag sets still work as usual.