MQ2.0 Image Puzzle

On Oct. 19th, the map image on the Muggle Quidditch CoCrossCampus site is updated with the following coded text.

M GCGA GQRE IANTD DAGQ MPYV BF XXBU
KKTHRP L XFE KVEEYZ GRLUB OXU LBPA:

K'IY NVXORFQ UYQ XHOAEFHK YBIS F NQWS,
ZOR J DRYZ PSE NED RTJDD FGYQ OHIY.

MC SRZLHZR EFQP QDOXEKIHH RXWK...
LLPW QEECK'J RCWRG, R WCHBX LVIX XLO.

AY UZPN FP RNOZ NHO BTWBVAX PO
GH FYFD CBT VPURX VIBU BSJZGPO YZH KN!