This is awesome but this is a rather strategic move. Hopefully RISC-V boards will emerge and this will become practical. Today, however, a RaspberryPI port could make more sense.
Obviously the HaikuOS developers have just found RISC-V easier and having more potential. Or somebody just has sponsored the effort.
The risc-v port probably benefited from the work stated above and stayed focused on a particular board.
These days I would say it is essentially a matter of focus. Considering that the Pi 4 is a tiny little beast hardware-wise (certainly good enough to run as a light desktop, which is what I use it for), Haiku would be amazing on it, but I just don’t see it happening (if it was meant to be, it would have come about by now).