I can vouch that this is accurate. While I'm obviously not a doctor, I process short term disability claims for a living and a torn meniscus is a common claim. When processing claims we have access to a medical database that uses historical data to give us recovery times for pretty much any surgery, and a meniscus repair(either open or arthroscopic) is a much longer recovery time than an arthroscopic meniscectomy.
A repair for someone like an athlete would be 140 days (maximum)
Arthroscopic meniscectomy, 84 days maximum.
That assumes no complications or setbacks. Basically 12 weeks vs 20 weeks