That's way too fast. But there's some unreleased tracks like Time Control so I guess they can make a mini out of that.
The Xmas comeback isn't really a comeback anyway since it's supposed to be a way of thanking fans and the promo period is gonna be so short.
f(x) release a mini album in 2012 after 1 year hiatus and with 5 weeks promo.
If it consider like this, f(x) pretty much had ZERO CB for 2 straight years cuz the promotion is so short and they just CB to thanks the fans for loving them, BUT NOT THE ACTUALY COMEBACK
And yeah, all Sistar "special album" like Loving you isn't an ACTUAL COMEBACK either cuz it was just a "special album" NOT for an actual CB.
However, they promoted throughout Music SHows and appeared in tv/variety shows for promotion. If it has a promotion and COMEBACK stages, then YES it is a COMEBACK!!
and EXO has all of those