(The URLs below are illustrative only, in the final setup they should point to old-bugzilla.wikimedia.org -- see T366)
Looking at https://bugzillapreview.wmflabs.org/T3347 , it has an
line (note T861 to change "ext_ref" to "Reference"), but no actual link to the original at https://bugzilla.wikimedia.org/show_bug.cgi?id=65088
I think it would be generally useful if WMF's Phabricator recognized the text "bz//65088//" as a Bugzilla link and handled it similar to how it treats magic codes like T//NNN// and P//NN// as special linked items. Or the conversion could create the link in markup as [[ https://bugzilla.wikimedia.org/show_bug.cgi?id=65088 | bz65088 ]] , or it could represent as "bug 65088" and let T687 make it a link.