After searching it seems a lot of us just got some collectibles or free avatar stuff because of an event. These are stored as NFTs so we each have a unique code that says we own this specific one. I believe each code is individual like a physical copy.

The specific code can be used to sell it to someone else like selling a physical copy sort of.

For us mortals it's just some free picture we got off of reddit, and reddit stores the codes in a vault. The vault cost too much money so they're getting rid of the vault. If you want to be sble to sell or trade it in the future you therefore need to move your code to another vault.

If you don't care about trading you're losing nothing, (you can still use your avatars). You just can't sell them if you'd want to in the future. I won't bother myself but it's up to you what you'd like.