Neither: their proposed design doesn't generate electricity from heat, so what they're talking about here is proving out the alternative mechanism of electricity generation that they propose to use. That's a valuable to demonstrate because it's novel, and necessary to eventually being net-positive, so showing that's possible shows that their eventual plan could work.

Yes, I figured that out long after my original post.

It's just that Sam's post didn't mention any (semi-)novel method for generating electricity from fusion, so the actual words - "they and their team have built a generator that produces electricity" - appear as either hype or non-information outside that context.