The automatic excommunication for consecrating a bishop without papal mandate (the exact penalty applied to Lefebvre in 1988 and to these six in 2026) didn't exist before 1951.

Pius XII created it by Holy Office decree specifically to counter the Chinese Patriotic Association's state-sponsored consecrations, and confirmed it in Ad Apostolorum Principis(1958).

Is it quite ironic Leo approved the Chinese state’s Bishop selection but excommunicated the SSPX? The official cause is disobedience as stated above, but Leo’s off-the-cuff remark clarifies it’s specifically for not obeying the Spirit of Vatican II.