They aren’t handing things out, they are offering an opportunity to buy items directly that you can get buying gems. Drop an equivalent amount on gems, watch the trade House, get your mythicals or legendaries. Or reach out to Support and offer to buy equivalent gems for items, worst they can say is no.
If you are so eager to spend money, do it. There are mythicals on the TH if you have spent the hundreds on gems. Or rage quit, it all works.
If you read the original post the keys, frags and mythics are extra items as a thank you. You buy gem paks get to keep the gems and also get free items too. There is no mention of them buying them from TH or via support by handing the gems back?
I guess you are not playing the Arena competitively? If you were, you would be upset at the huge advantage now given to only the 'chosen players' with this offer with all these Mythical items. It is not a level playing field anymore. Events like this should be for everyone or else we should have our own server with arena/leaderboards if the game is not being treated as the same for everyone.