It is possible to doublecast warcry by using the node that makes you warcry at the end of rampage, putting rampage on then same button as warcry in human form and then holding down rampaging when low on rage so that you exit wearbear form into human form at the end of rampage.
This casts warcry once at the end of your rampage and then again in human form.
Here is a video of it:
