Writing this answer I realized that Hayabusa-2 has two very similar looking circular flat disks that serve as it's high gain antennas. One is dedicated to X-band (7-8 GHz) and the other to Ka-band (32 GHz).
In my second answer ever here I concluded that a "phased array" would be one that is steerable by adjusting the relative phases of the different radiating elements within the array, and so the device shown there would not qualify as a phased array proper since the beam shape and direction was fixed. If you wanted to point it somewhere else, you'd have to change the spacecraft's attitude.
So what about Hayabusa-2's high gain antenna-disks. Can these steer to some extent, or do they point in one direction and require the spacecraft's attitude control system to point them at Earth?
The disks are about 90 cm in diameter. That means for Ka-band with a wavelength of 9 mm, the disk beam will have a beam width of only about 1 degree. That should be no problem, but it points other instruments in possibly un-useful directions. Point-ability might have some useful advantages, but it's also a level of additional complexity that can fail, more weight, a little more power, etc.