Was St. John referring to schismatic bishops in describing the Antichrist in 1 John 2:18-19?

> 18 Children, it is the last hour; and just as you heard that antichrist is coming, even now many antichrists have appeared; from this we know that it is the last hour. 19 They went out from us, but they were not really of us; for if they had been of us, they would have remained with us; but they went out, so that [a]it would be evident that they all are not of us. (1 John 2:18-19 NASB) What was St. John describing when he said the words "they went out from us but they were not really of us". It's like the schismatic bishops, they claimed to be inside the Church, but they were not really belong to the Church, because schismatic behavior makes one outside the Church. - Canon 751 Cardinal Sarah stated, **"to oppose the Pope is to be outside the Church"**, and we have seen so many bishops and cardinals opposing Pope Francis, but still insist they remain in the Church and not outside. [Cardinal Sarah: To oppose the pope is to be outside the church](https://www.ncronline.org/vatican/cardinal-sarah-oppose-pope-be-outside-church) Antichrist or spirit of Antichrist won't submit to authority like the Pope, like Lucifer won't submit to God uttering "Non-Serviam". Was St. John passages in 1 John 2:18-19, be appropriately pointing to schismatic bishops of our times?