So I had this theory about the Cybermen we see in the series 10 finale.
I think the colony ship was ordered by the authorities on Mondas when they first started to realise what their world is becoming. A skeleton crew of 50 then went to pick it up from whatever spaceship company they ordered from, and on the way back encountered a black hole. As time went on, the people of Mondas found new ways of survival in their decaying environment. The descendants of the crew on the ship contacted the Mondasians, and upon figuring out they both had a similar problem, shared plans of survival. That is why the Cybermen on the ship are so similar to the Mondasian ones. (In the ship's computer the place of origin was set to Mondas by the skeleton crew for the future use of it, which is what Missy finds.)
Please note my knowledge of Spare Parts is limited (I have only listened to a small part of it) so if this contradicts anything there let me know.