The pair filmed the scene during a visit to Pinewood Studios in April 2016.
For anyone playing a non-crucial role in any film production, there is always an anxious wait between filming and opening night to see if your scene(s) made the cut.
Even the Royal Family aren’t above this as it turns out that at 6’2 and 6’1 respectively, Princes William and Harry were simply too tall for the role and towered over their shorter Stormtrooper colleagues.
Prince William and Prince Harry visited the @starwars film set at Pinewood Studios in April 2016 to recognise the wealth of British creative talent involved in the production of the Star Wars films. pic.twitter.com/GcoooJjLDU
— Kensington Palace (@KensingtonRoyal) December 12, 2017
According to an unnamed source in the Mail on Sunday:
'Stormtroopers have to be exactly 5ft 11in. At the time we shot it I think the feeling was that the scene would make the final movie. The scene just didn't work for the final cut so it was left out.'
Apparently, the brothers didn’t find out until they watched the premiere at the Royal Albert Hall that their acting handiwork hadn’t made it past the cutting room floor.
According to an interview for ITV in December, John Boyega said he informed them:
“'I did personally apologise to them [the Princes] yesterday and said, 'Sorry you were cut out of the film.' And Will was like, 'I probably just need to work more on the skills.' I was like, 'Maybe, bruv.'"
Via: The Telegraph