Even in the modern version, a Haiku is a very short poem, with a set formula of syllables or on. Beyond that, it contains a juxtaposition of two ideas, and a reference to nature. The format and aspects of content are set, or it is not a haiku.
But within that form you can express whatever you like – the world is grand or my mother-in-law sucks (the sound of a whirlpool, for example). Chocolate is my love and my demon or I have my doubts about Heisenberg.
The choice to write a Haiku or an NIH grant, of course, is yours.