It may still have a chance to make another pseudobulb. Though it would have been nicer if it were at least 3 older ones..but who knows, sometimes the plants have a certain fighting spirit.
I think you may have to keep it a little more moist. I find the Milts and their hybrids thirsty.
I have a Miltassia which I have left in my growcamp outdoors during winter, and come Spring, some of the pbs got yellow like yours, and there are some that are still green but you can just see the struggle the plant endured during the cold season. Now that it is really getting warmer, with heat waves coming in now, I have stepped up watering, and been showering the plants as often as I could. I can do this since it is outdoors in the screened growcamp, so it gets full sun for about 3 hours in the morning and shade the rest of the day. Cross breeze all over the orchids in the growcamp.
Here is the photo of my Miltassia: it is not in the best color or condition yet, but I see new growth and with that I feel reassured the plant is bouncing back.
Good luck on your Milt!