A product is made as long as it turns a profit. When it stops doing so, it goes out of production. So, are these guns "relevant"? Sure, they are great shooters...but so many guns today are great shooters that it hardly makes any difference. Depending upon budget, a Nemesis Arms takedown, a Sako TRG, a Remington R5, one of the numerous Savage target/varmint/LE models, or any of a host of others rifles will deliver the goods. But I think the typical buyer of an SSG is looking for more than just accuracy; he wants the name, the cachet, the "legacy" that goes with the Steyr-Mannlicher name.
If these rifles were not stamped with that name, how many people looking for ultimate accuracy would buy one? A plastic stock without any metallic spine or chassis...an expensive all-plastic magazine with a known reputation for cracking...virtually no aftermarket accessories available...expensive proprietary scope rings...yep, cutting edge all right.
If you want one because of what it is, i.e. a classic, classy Austrian design with history and style and tradition...well, that's more than enough reason to get one. But in many respects, it's the only reason.
Edited to add: Regarding "relevance", do any winning competitors in any kind of accuracy shooting event still use these guns? That's probably the best test of relevance.