I have worked LUN configuration for Hyper-V. In general, there are many points need to follow to do the best service. But now i can say you can do go ahead for the single volume with single LUN for hyper-V because the lun you want to assign to the hyper-v host machine would be a bigger size where many VMs will be run.
1)If VMs critical for the production then volume must be a guaranteed(Thick) volume so that no need to monitor everytime of the thin volume space.
2)IPOS need to calculate before the creating the LUN from the aggregate.
3)One volume one LUN will help if migration required in the future.
Thanks, Many more points are there to keep in mind for assign the LUN to the hyper-v