New type

I think a new element night should be added to weaken light and ghost

[Koenaj]

If you would've looked a little further, you would have found more topics that suggested this.

http://www.haypi.com/forum/viewtopic.php?f=642&t=20939 See #3
http://www.haypi.com/forum/viewtopic.php?f=642&t=20540
http://www.haypi.com/forum/viewtopic.php?f=642&t=20112
http://www.haypi.com/forum/viewtopic.php?f=642&t=19894

Those are just a few examples of predecessors.
To answer your question: I'm fairly sure Haypi will add more elements in the future, but keep in mind Ice came only two updates ago, so it's not like they haven't added a new element in ages.
You can't expect Haypi to create a new element + 10 monsters every other week.