[Q] Giveaways Of Keys From Fanatical Bundles

If you havent activated them the keys should be vaild.

If you are sure you never used them or gave them away to someone....then they should still be okay and you could make giveaways for them.
They only get tied to an account if you activate them, not just by buying them.
And if you bought a bundle twice it's impossible to redeem the second key on the same account.

No site auto-binds keys. Fanatical/Bundlestars isn't known for expiring keys (like GreenManGaming does) or overall unreliability (like IndieGala or G2A or junk-bundle-sites), so in theory (as with Humble and Groupees) the keys from the site should be fairly reliable, no matter how much time has passed since their purchase.

There's always a theoretical risk to especially old keys, however, and winners are not required to agree to a deletion if your key no longer works (though it is understandably considered quite rude [not to mention indicative of them being autojoiners] for them not to, if you made it clear in the giveaway description what the circumstances were). As such, it may be best to avoid public giveaways (and their associated toxicity) for that reason (favoring instead trustworthy groups or SGT-filtered invite giveaways), and make it clear from the start that the keys are old and you'd appreciate a deletion if it does happen to come down to that.

Which bundle was it? There was a game from a Fanatical bundle that had an activation deadline.
See this post: PSA: Nemesis 5 Bundle Fall of the Dungeon - Activation ends 9th March!

the best is to join a group whose rules are to agree to delete giveaway if key is not valid, you can try there.