I've always been 100% fine with old seasonal items being put up on the cash shop. They did it with the All Saint's Wake, they did it with Starlight Celebration, they're doing it with Heavensturm, and I think it's really good of them to put up all the old stuff on the cash shop since everyone who has been playing the game since launch of 2.0 has had a very fair chance at every one of getting these items in-game.
The only reason they sold the old hats for 10 gil last year, I assume, is because the majority of the current playerbase didn't play 1.0 and missed out. This way, as 2.0 is more accessible and populated than 1.0 was, moving those items to the cash shop keeps them able to be purchased all year round.
So I'm perfectly fine with old event items being on the cash shop. It keeps the events fresh and clean while still giving players the option to grab the old stuff if they so choose.
