So I was playing the new Operation: Spearbreaker missions and in the first mission you start out with just Sunray 1-1 but you later pick up other units some of them being standard marines. These marines (and maybe the other units as well) were not affected by upgrades unlike ones built from the base. I could tell because even after researching Combat Technician they still wouldn’t repair buildings nor did they have the extra marine added from New Blood. This is the only mission I’ve noticed it on but I don’t know if it was the same throughout the main campaign.
PS: the hologram in the same mission (Gatecrasher) uses the model for Atriox’s Chosen but the icon and subtitles show and say Warlord.