A question about remastered sound track

On mission 11 of homeworld 2 classic, there’s an unique soundtrack, rendering the furious fight around the debris of bentusi ship remain. In the file list, this track was named “battle_04 alt”.

In the remastered version, the bgm of this same mission was replaced by a normal vager theme, which is a totally different track. The “battle_04 alt” file still exists, but it contains the different music as well.

And futher more, the original 04alt track wasn’t in the OST either, even though other four unreleased tracks are included.

I think at least it should be in the OST. Why did this track vanished? What happened to it? What’s its story?

Anyone know anything about it?