US News no longer uses acceptance rates in their calculation and enrollment % is also not a factor. The only way moving to ED/RD would help BC’s ranking (if that’s a factor in making the change) is if they get applicants with higher SAT/ACT scores and GPAs or their perceived prestige goes up (deans of peer schools and HS counselors).
https://www.usnews.com/education/best-colleges/articles/how-us-news-calculated-the-rankings