Nahmanides notices this peculiarity and explains it as follows (attempting a sound translation):
Behold the altar of the incense was from the inner vessels, it is fitting that it should mention it with the table and the candelabra, for the mizbe'ach was with them, and so did it mention them during the construction in the portion Vayakhel. But the reason to mention it here after the Tabernacle and all its vessels and the sacrifices, is on account of its saying at the culmination of it all, 'and be sanctified through My glory... And I shall dwell amongst the children of Israel', it says that the obligation is still upon them that they should make and altar for the burning of incense, to burn for the glory of Gd...
(There is more in Nahmanides' writing starting here, which I am sure is where the truth lies that I am failing to pick up on.)
At a cursory glance, the reason its mentioned here is: because Gd mentions His dwelling amongst us, He informs us that there is one more thing for us to make for Him... But how does this answer the question? It doesn't seem to address at all why the golden altar should be mentioned separately. What am I missing?
Thank you for your thoughts!