A new blog post on the Dota 2 site confirms that Valve is staffed by Grinches, because Frostivus is cancelled. (And there’s no Greeviling, either.)
Okay, so “cancelled” isn’t the right word – if anything, they’re doing exactly what we wanted them to do and are telling us “no, it’s not happening” rather than leaving us to wonder when it would be. Still, it does mean that there won’t be a holiday-themed game mode this year.
It’s basically for much the same reasons as No Diretide: it would take resources away from other areas, and it’d be a bit of a waste of time. Valve are working on a major engine update to Dota 2 which will allow the quick and easy creation of new game modes, and any work done on them now would basically go to waste as soon as the engine update is released because they’d have to be rebuilt from scratch anyway.
In Valve’s words: “In the past, our Diretide and Frostivus updates contained game modes that were very time consuming to build and maintain, and would need to be rebuilt from the ground up after the release of the engine update. […] The mode would quickly become obsolete when the engine changes arrive, and […] building it would have taken resources away from the work that needed to be done to ship the engine change itself.”
The engine update is scheduled for the first half of 2015, but we will be seeing some new stuff before then. The post confirms that the next major update will be the New Bloom Festival in February, but Valve notes once again that they “will continue to avoid building new game modes until the engine improvements come along.” So whatever New Bloom involves, it probably won’t be the Year Beast. Which may actually be a good thing, come to think of it.