.... Related question: why do you think there is nothing new being built in the 1900/Saab 340 class? Anymore there are Caravans/Pilatus at 9 seats, a couple 50-ish seat props (ATR and Q) and then the jets, and even those aren't being built in 50 seat variants anymore.
Not quite. There are five airframe designs (in the Beech 1900-Saab 340 class) currently available new, all but one built far away, and all the latest tweak (various new technologies, glass cockpits) on a venerable design. None are speed demons. All have STOL capabilities, are high-wing twins and are primarily in use in 3rd world countries, in military variants, and dropping skydivers or for cargo. Most are boxy, lumpy and not very sleek. Several have history as regional airliners in the past, and/or elsewhere in the world. All but one (Viking Twotter) have retractable gear. No 50-seat jets, since plenty are or will be available soon in the used market.
LET L-410. Originally Czech, now built in former USSR. Twin turbo-prop, 19 pax, 1971 original design, more than a thousand built.
Dornier DO-228 NG. Germany, twin turbo, 19 pax, 1981 original design, around 300 built.
Antonov AN-28 / PZL Mielec M-28. Soviet design, now made in Poland. PZL is now owned by Sikorsky / Lockheed Martin. 19 PAX. Around 200 built. USAF uses them for Special Ops work.
CASA C-212. 1971 Spanish design, now built in Indonesia. 500 plus built, 26 pax. US Army & Air Force use it.
Viking Air DHC-6 Twin Otter. Viking builds the newest version of DeHavilland's classic design in Vancouver, Canada. More than 900 built. 19 Pax. Available with floats or skis, too. In use nearly everywhere. new and old.
Coming from Italy:
Tecnam P-2012 Traveller. New design and sleekissima. High-wing, fixed gear, 9 PAX , Piston twin. Co-conspirator on the design is Cape Air, to replace their Cessna 402s. First flew a year ago, now in flight testing, expected to enter service in 2019. Cape Air has ordered a hundred.
Sources: Wikipedia, some manufacturers' websites.