Earlier in this video he gives his opinion on the IBM PS/2: https://youtu.be/yoAH1aHmwR0?t=655

Antichrist is only mentioned in the 1st and 2nd letters of John, where it refers to many antichrists (1 John 2:18), who are identifiable because they deny the Father and the Son (1 John 2:22), and that Jesus Christ has come in the flesh (2 John 1:7). The term simply means, 'against Christ', so anyone who is against Christ could be labelled such, even if they didn't match the description in 1st and 2nd John.

So antichrists existed when these letters of John were written and an innumerable number of them have existed over the past 2,000 years and exist even today. While antichrists would likely continue to exist while the events in Revelation occur, they are not described as having any role in the events described in Revelation.

The reason people link antichrist to the beast or false prophet in Revelation is not due to the writings in the New Testament stating that there is a link. It is more that any being who is against Christ, including those in Revelation, are likely to deny the Father and the Son and deny that Jesus came in the flesh, so, it isn't difficult to find numerous antichrists throughout the past 2,000 years that Christians could identify as being an antichrist and since, for each generation, their time was, to them, the end of time, because the future hadn't happened yet, it was easy for them to think of these antichrists as potentially being the beast or false prophet of the end times described in Revelation.

Over time, this traditional link between antichrist and the beast or false prophet became very strong, in spite of not being stated in scripture and more tradition has grown up around linking antichrist with the beast or false prophet, creating traditions upon traditions, upon traditions, not of which is substantiated by scripture or any other early writings from the Christian community.