I am curious about this as well. ORBX is a close partner of Asobo/Microsoft and Asobo has used ORBX for content they have included in the sim updates.
Looking at some of the previews of the UK update it sure looks like they are using some ORBX London assets??? The ferris wheel caught my eye as looking the same as the ORBX one?
Begs the question if the Landmarks London City Pack become obsolete will they give us some credit towards other ORBX products? Will they significantly update the London pack to only add things not in the UK update and still future improve on it?
Guess I should go join the ORBX forums given I have plenty of their products.