Only found out about this about 30 minutes ago. A gamer and gun enthusiast by the name of Arto Roth has produced and released updated infantry weapons and heavy weapons guides. Only available as PDFs, there is no indication that they will be available in other formats and there's no indication that the author intends to produce any other books.
Despite being made for 2nd/2.2 of T2k, these books feature many modern weapons from the 2000s up to 2020 alongside all the earlier items we'd expect so the books are very well suited for Merc: 2000 and Dark Conspiracy. However if you want to use them for a 1990s or early 2000s timeline for Twilight: 2000 you will have to go through both books and decide which weapons are unsuited for your timeline.
https://www.drivethrurpg.com/browse....or=Arto%20Roth