Coded message from Prof. B

On December 23, 2020 (2020-12-23T10:28:44Z), a user named Prof. B (Prof. B#9117) posted a message along with an image in the #pizza-delivery-arg channel on Discord. A few days earlier, a mysterious comment signed "Prof B." was posted on the "Meet the Devs" code puzzle page, signaling that something was afoot.

Message
"'A Myonmas Gift, trace is running I must go.'" Note: The wiki software may have changed the original image file. Use this link to download the original file, or download the original file from Discord.

Ciphertext
Original format: DZRHI VEUOL PTFRV ONSHK KIETO ZQRQJ YAEZK RFTGB QCSGO OGWDS VWCIE KGTJP HKPMK EHWVP ZFGVP OPSQS LREAM YFEHQ GZPWM MFKFR JKANP UDCQY ALANQ GGIOO ITPBT MAMxx A=NGx DRHxx

On a single line: DZRHI VEUOL PTFRV ONSHK KIETO ZQRQJ YAEZK RFTGB QCSGO OGWDS VWCIE KGTJP HKPMK EHWVP ZFGVP OPSQS LREAM YFEHQ GZPWM MFKFR JKANP UDCQY ALANQ GGIOO ITPBT MAMxx A=NGx DRHxx

On a single line with spaces removed: DZRHIVEUOLPTFRVONSHKKIETOZQRQJYAEZKRFTGBQCSGOOGWDSVWCIEKGTJPHKPMKEHWVPZFGVPOPSQSLREAMYFEHQGZPWMMFKFRJKANPUDCQYALANQGGIOOITPBTMAMxxA=NGxDRHxx

Metadata
The  file has been examined for metadata using a tool called exiftool. The full output of the tool is too long to be included on this page, but a list of some interesting metadata fields have been included below:

Date/Time Created              : 3021:12:23 17:03:59+00:00

Caption-Abstract               : humans need By-line                        : Prof B Object Name                     : humans need Time Created                   : 17:03:59+00:00 Keywords                       : Myonmasgift Copyright Notice               : Not Prof B

Date Acquired                  : 3021:12:23 17:04:17.335 Rating Percent                 : 99 Create Date                    : 3021:12:23 17:03:59.850 Rating                         : 5

Rights                         : Not Prof B Subject                         : Myonmasgift Title                          : humans need Description                    : humans need Creator                        : Prof B Last Keyword XMP                : Myonmasgift

Geometric structure
The geometric structure seen in the image appears to be "a 6-cube projected into the rhombic triacontahedron using the golden ratio in the basis vectors." The full source image can be found on the Wikipedia page on quasicrystals. The image caption on the page further states: "This is used to understand the aperiodic icosahedral structure of quasicrystals." The image can also be found on the Wikipedia pages on the 6-cube, and the rhombic triacontahedron.