At this point they have long abandoned French House and are working more with Electro House. There are typical orchestral elements in the album, as it is common with soundtracks. The more slow and ambient-y that aren't orchestral, are definitely Progressive Electronic in the likes of Vangelis, Klaus Schulze etc.
Tip: it's always a good thing to have a look ...
It is often not possible to pin down a single genre to an album.
This review by Heather Phares identifies electronic and orchestral elements as mentioned by the OP:
Working with the London Orchestra, Bangalter and de Homem-Christo fuse electronic and orchestral motifs seamlessly and strikingly.
The reviewer also notes that
for most of Tron: Legacy, ...