Legally, no.
I would point out that brides are often the most difficult and demanding clients. Would you be confident tackling a change of mind or a hissy fit without being used to handling hair?
It's one thing being able to do GHD curls or a messy bun, but it takes a lot of learning and practice to get perfect barrel curls, or pin a perfect french pleat so that it stays in position all day and evening.
In the olden days when I trained, we did 2 hours of hair up training a week for THREE years! Plus I was fortunate enough to work alongside some amazing hairdressers who were skilled in the subject.
The majority of hairdressers are uncomfortable with hair ups at the best of times.