Obviously not a cue maker here, but I do have some thoughts.
Pasteurized milk has few if any active enzymes in it. Those that perhaps might exist (I won't bother naming them) would likely have no effect on modern adhesive.
More likely the residual presence of nutrients from the leather could provide a culture media for microorganisms that would break down the leather at the interface with the adhesive. Considering this is leather, it would most likely be fungus.
In addition, the shearing forces generated from compression (pressing) could damage the interface between the adhesive and the leather.
I do agree, the process could threaten the adhesive bond.
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