They didn't use Bryant at leadoff at all last year. I'm looking at a list from a NBC sports Chicago article and they primarily used Schwarber, Hayward, Almora, Zobrist, and gag Daniel Descalso. Unless I read wrong and you meant Bryant as the 2 hitter?
The Cubs haven't had a true leadoff hitter since Dexter Fowler left after the 2016 season and it's been a big problem. Bryant will be better than most of the guys they had last year. Hayward and Almora were particularly atrocious. Weirdly enough, Rizzo has been their best leadoff guy when they used him and has a career .462 batting average at leadoff since 2017. They should use him if Bryant bombs.