Probably not.
Highly doubtful. Depends on who plays, and how Brexit shafts freedom of movement, but I'd be very confident of 20,000+ crowds at Falmer, with a probable sell-out if it's England.
It was a good turn out despite the Albion not plugging it properly, and many considering not returning due to the club not having the usual matchday facilities open.
I do know of several people who have been to the Amex on that day only, and were genuinely disappointed with how poor the set up...