Dr Peter Masters (successor to Spurgeon at the Metropolitan Tabernacle) writes on Article XXVI:IV
This last paragraph is regarded by many who affirm this Confession, as the only debateable statement. There is no disagreement among them as to the heresy and darkness of the Church of Rome, nor of its instrumentality as a tool of satan down the ages. The papal system is certainly utterly anti-Christian in spirit, form and effect. The issue is-- will the last pope of time be a servant of the coming antichrist or will he be the antichrist himself? Or, will the Church of Rome itself prove to be the antichrist? The 'man of sin' may turn out to be a person or even an atheistic ideology, but very few teachers today are prepared to make a definite identification. However, at the very least it must be said that the office of the 'Pope of Rome' is in the power of antichrist, and any serving pope is a man of sin and a son of perdition who exalts himself against the true Word and the message of grace.
My understanding is that it is possible to deny Article XXVI:IV and still be regarded as a strict subscriber to the Confession. Sam Waldron, in his commentary on the confession writes,
'Many of those who hold staunchly to the 1689 Confession doubt the value of its dogmatism regarding the pope being the antichrist. The writer is among these. This is one of those statements which would properly be deleted in a revision of the Confession. Such a deletion must, however, be made, not because of any weakening of our convictions about the apostate condition of the Church of Rome, or the wicked and heretical character of the claims of the pope.......'