I'm in the same boat, I have a couple of model year 2000 mills. I was told I have a brush type rotary table and indexer but my drive board is the same as yours. The best way to know what you have is to look at your plug end on your rotary. If you have a single large connection, then you have a brush type rotary. If you have two smaller connections, then you have a brushless type rotary. I have both types in my shop and the brushless uses two cables instead of one large single connection. Hope that helps.
I was looking at the HAAS website and it appears that there is an even newer third generation high speed drive available.