No need to be embarrassed - I thought the same thing when the US update released. That's my point, why is the main update always so big when the new scenery is apparently separate and optional?
Yeah, the actual release notes for the 1-13-16-0 update part are not very extensive:
https://forums.flightsimulator.com/...-now-available/365854#release-notes-1-13-16-0
There must have been some crossover since I found that Barra airfield was in the sim (it wasn't before) so maybe some world updates that were needed to accommodate the UK & Ireland scenery updates.
I am waiting for a delivery to arrive so will run the sim after that has completed and see what's what.