Sorry for the delay in responding...I wanted to check with the rest of the committee on this one.
Formats does not directly address the idea of what IS volume 1. Formats says that volume 1 has the full brief contents and whichever part of the full contents applies to that volume. If you consider the preliminary volume as your volume 1, then they would be there. If you do not consider the preliminary volume, volume 1, they would be placed in volume 1. One committee member brought up the point that the table of contents really isn't applicable (most of the time) until you get the to beginning of text...and the preliminary volume is usually the pre-matter - not the main body of text. So the table of contents wouldn't really be useful there.
But again - it is your decision on what you consider volume 1.
Sorry I don't have a solid answer for this! The committee was split. I guess it's something we will have to look at adding to Formats - or clarifying.