That's a really bizarre claim.
That which is counter to God’s word is Counter to Christ.
Yes, it is.
Protestantism, being counter to God's Word (and true to the "God(dess) in the Bathroom Mirror"), is counter to Christ.
Roman catholicism is the essence of Antichrist in the Revelation.
Protestants are protesting Antichrist.
A man calling himself a priest is antichrist. Calling that man “Father” is antichrist.
Bowing to the Mary/Ishtar proxy is antichrist.
Reciting a prayer from a book, rather than from your heart is antichrist.
Reciting of creeds that mix truth with untruth is antichrist.