I think the discipline is being split into two groups.
Technical documentation is increasingly being handled by CAD, using the same drawings and models used to design and fabricate the products.
Marketing images are all photography or 3D, or some combination of the two. Any illustrations are usually less technical, more info-graphic, and are produced by graphic designers.
Post-secondary education is all about specialization, and usually targeted to the realities of the job market. You'll have to decide if you're more suited to the technical CAD side, or the more visual Marketing side.
I think there's room in the job market for someone who's proficient in both areas, but your job title will probably be one or the other.
Hi. technical illustration has not been taught as a main stream course on its own since the late 1980s here in the uk. Technical illustrators are a rare breed now in the UK as cad and then solid works and other 3D modelling software has led to the cad design engineer creating the exploded cutaway illustrations for most publications. Although i am told companies are trying to return to the traditional look/style of a thick thin illustration but struggling to get illustrators.