Put me in the camp of “this is a bug whether devs cop to it or not.”
Because if it’s “working as intended” then the offer is supposed to help kingdom progression. This flat-out doesn’t.
The argument for all other “worthless” offers can be made that they are actually worth something because potential uses exist.
Like crafting materials might help if RNG denies enough mythics to necessitate a depletion of diamonds. That will never happen — but it could, so that offer isn’t technically worthless. Keys and chaos shards, same thing. Ingots are way more of a stretch, but (I guess?) a person could run out if enough weapons were dumped into the game, or if said person stopped playing PVP/delves. Medals, colored deeds, and delve treasures are overpriced (but what isn’t?), but at least those are drops in buckets toward kingdom/faction progression…
But copies of already mythic cards due to a kingdom progression requirement for medals? Straight-up nonsense. The offers should offer MEDALS, not try to help a player ascend a troop that CANNOT be ascended.
Would the offer be bought if it were “fixed?” I’d not recommend it, as the medals aren’t worth the gems.
But at least if a person were offered medals for gems in this event, they would be able to progress a kingdom.