This is it. I've never used the video feature of Sonar but I have often opened that view by mistake.
It's plainly not there in HS , I checked. The " Make
soundtracks for videos" might be referring to the audio, not the video.
Some of the confusion is that they did not make help files for HS, you are using the same documents that all versions use so it is left up to you to sort out what features you have. I myself have no issue with this as it's never a huge surprise to go to use a fancy feature and it's just not there. I really didn't expect much for only $50. There's a very short list of missing features for what I do.
If that feature is important to you then I guess you'll need to upgrade to Artist, this is the nature of price points for all software.
If they do anything to make this clear they should add "Video" to the "Versions" list.
http://www.cakewalk.com/Products/SONAR/Versions#start