a lot of buildings miss construction animation(most grievously the gateway, but all the minor advanced buildings as well). And then there is the citadel of adun. It lacks in lore background and it only contains a single upgrade for a unit it has no connection to.
I almost took this seriously, but then I saw this was in space junk. Was about to launch about how wrong you where about the animations too >.>
For construction animation, do you mean when the building is being produced, or when the building is making a unit? If I remember correctly, the warp-in animation for buildings does change slightly to show how far its progressed towards completion. For the citadel, it has 2 upgrades: blink for stalkers and charge for zealots.
It is named Twilight council, so it is sc1 drie talks about methinks. Adun might be one of the sacred places of the templar caste, i do not know, but it has some connection.
Furthermore, the robotic support upgrades lack fluff in their names. usually upgrades are called 'gravimetric drives' or something like that, but for the reaver upgrades it's just 'upgrade reaver capacity' and 'increase reaver capacity'