This statement is inscrutably generic. Are there examples of behavior which went unaccounted? Or, what prompted this? Also, is it common for projects to have mod teams? This is new to me.
They don't want to make the specific issues public, but take a stand against the core team being non-responsive to issues raised by the moderation team. We don't know what or why beyond the fact the moderation team feels it can't perform its job when the core team does not submit to the same rules the rest of the community does.