As part of station redevelopment works in YPR, I think PF 2,3 wont be available. Hence they are cancelling trains or else diverting. 12257 YPR-KCVL is cancelled for 1 month from 20th /21st Aug as well. Similarly heard that SMVT-MAQ is likely to be diverted via BAND ,and by passing YPR. Probably that could be one reason