The airline is closing all its long-haul bases and returning its 787 fleet.
The 1100 pilots and cabin crew employed at Gatwick will be laid-off. It
will retreat to its origins as a small Nordic short-haul low fare carrier:

https://www.thetimes.co.uk/article/1-100-uk-jobs-go-as-norwegian-air-abandons-long-haul-services-fzw956s6w?shareToken=61da473a9f7d23c10a593ab178d9f e55

So that's another big loss for Gatwick. Virgin has permanently pulled out,
and BA has moved out at least temporarily; it's not clear how many BA
flights will return, or when. Previous departures include Monarch, Thomas
Cook and Thomson (bust), and most US carriers (who moved to Heathrow).