The tech has been around for a while and is pretty cool. You can actually get metal infused plastic spools if your printer can handle it, but the good stuff requires the print to be sent out for final processing. The stuff BMW is doing is next level, though.
Sintering (the non-3D-printing version of what BMW is using in the article) has been used by Smith and Wesson for decades. All of the hammers and triggers on post-90s or so revolvers are sintered.