It could easily be mandated by a customer's project specification for a job that is going to be fabricated by your employer.
Depending on the welding process and the applicable welding standard, it could be a requirement that was overlooked previously. In particular, I am thinking of gas metal arc welding using the short circuiting mode of transfer. Several welding standards such as NAVSEA TP248 or ASME B31.3 High Pressure are examples where welder performance tests are required to be evaluated by bend testing.
Best regards - Al
The gas company I worked for last year did the same thing for any welders workin for it. After one year, they'd bring you back to their test shop to take all the destructive test over again no matter where you was at or what you was doing. Don't really make much sense but as long as they pay, whatever.