I'm glad there's finally a way to get the "Bomb Dance" emote for those (like myself) who weren't here to participate in the event the last time around. Obviously I would have preferred to see it and various other past rewards be available through in-game events rather than the cash shop. However, assuming you're determined to release these items as microtransactions, I think I'd prefer it if you used the method ArenaNet used for GW2 instead.
ArenaNet allowed players to purchase past/expired GW2 "living storyline" events for a minor fee. In this way, players who missed these events were able to experience them (and earn the rewards through in-game methods) even after the event period had ended. Like I said, I'm happy to finally have access to the "Bomb Dance" emote, but I would have liked to have experienced the event surrounding it firsthand with my character. With the use of instancing and phasing (something FFXIV already uses), one would think ArenaNet's method would be applicable here.
Another example: I had a lot of fun with the "Fleece Force" event some months back, and you'll probably eventually sell the rewards from that event (i.e. the lamb minion and various sheep helms) in your cash shop. However, I think it's a shame that new players won't be able to experience the work and humor that went into that content as it was originally presented.
Wouldn't it be cool if they still could? If you're going to (hypothetically) eventually sell the lamb minion and sheep helms through your cash shop, why not sell that entire quest event as a package as well? Perhaps priced as a cheaper alternative, since players will still have to put in the effort in-game to earn those rewards (in-game), while also retaining the option to purchase the rewards outright for those who could care less about the story.
Anyway, just a suggestion. Will the Lightning event items also eventually make their way to the cash shop?