BTB 2.0 was and is something else; the increased player count BTB is not what was in development for BTB 2.0. The 24 player BTB is an upgrade to the original BTB to be sure, and I can understand why people get their wires crossed thinking that it is BTB 2.0. However, the original BTB 2.0 was canned during development AFAIK. I don't know if it will be continued, restarted, or spiritually rebooted ever but what launches in Halo Infinite is very much not BTB 2.0
So Theorry brought this to my attention earlier in this thread, no idea how accurate xboxygen is - or if they have old information available, this is what they said:
Those who thought that 343 Industries would rely on the achievements of the license are wrong. A new game mode is expected to emerge and become the flagship of Halo Infinite multiplayer.We will not mention the name of it or other details about it which will be discovered very soon, but it is indeed a mode of massive war, a more advanced evolution of the BTB that should be presented. in detail. Another important game mode should also present itself, but later, and according to the same sources, no Battle Royale mode is planned for the moment for Halo Infinite.
article: https://www.xboxygen.com/News/37037-Multijoueur-de-Halo-Infinite-les-rumeurs-et-nos-infos-spoiler-E3