Apparently mazda is committed to gasoline... although they are also announcing plans for electrification... No judgement... just interesting.
I think Mazda is right in that it's a relatively safe bet that gasoline engines will still be around for a bit, even if certain countries and cities are trying to phase them out. If I had to guess, there's probably some financial motivation for them in that they don't have the same amount of resources as some of the larger companies, say GM, VAG, or Toyota, and they're already put a lot of effort into their next generation gasoline engines as it is. So for them, it's probably more prudent to stay the course than do a complete shift to new technology. Besides, they always have the option to share technology and facilities with other companies. Look at Toyota and Subaru. Or Toyota and BMW.
Edit: Going back to re-read the article, it even talks about Mazda and Toyota partnering up. Man. This is what I get for commenting on an article I've read three days ago, I look like an ass.
If I think you mean that Mazda is banking that other countries will still want gas cars, that's a pretty realistic point. For example, countries like India and some South American countries don't have as stringent safety standards. I think that Tata Nano cost a few grand in India but when they were looking at bringing it stateside the price ballooned to over ten grand because of all of the additional safety features needed to make it NHTSA compliant.
It's interesting that they chose a supercharger over a turbocharger for their setup; the conventional wisdom is that turbocharging is more efficient than supercharging since it derives its energy from exhaust gases, whereas a supercharger is usually hooked up to an engine by a belt so it's sapping power from the engine. In normal use cases a supercharger has the advantage of instant response (whereas the turbocharger needs time to spool up after you throttle up.
Considering the focus here is on efficiency, I wonder if Mazda uses a supercharger because they can decouple it from the engine when there's not much load (most of the time), and the small efficiency penalty is offset by the lack of spool time and less backpressure compared to what you get with a turbo setup.