The idea is not bad, and I fully agree with you, because they haven't been updated in a while.
However there's so much stuff curently happening on cubecraft, and I highly doubt, that that's a priority at all.
Updating the most popular gamodes is one of the biggest priorities as you can probably imagine, because many players play them, as well as fixing their bugs and glitches.
19 helpers got promoted today, which is also a factor.
Just be patient, because when things cool down for a bit, such things like adding new seasonal maps may become a priority.