Interesting dynamics and history are at play with Bandai Namco's creation of Project Vein.
You see, Bandai Namco basically lucked into the gravy train that has been the Dark Souls series for the past five years. FromSoftware worked with Sony to publish the first Souls game, Demon's Souls. However, due to its initially lackluster sales performance Sony wasn't particularly interested in going through the trouble of bringing Demon's Souls to the wider world. Niche game publisher Atlus saw potential and stepped in to bring the game to North America where it became a cult classic. Unfortunately, sales still weren't huge and no publisher seemed overly eager to publish Demon's Souls for the European market. Even traditional FromSoftware partners like Tecmo Koei and Ubisoft turned their noses up when approached. That's when Bandai Namco stepped in to publish Demon's Souls in Europe, laying the groundwork for their future partnership with FromSoftware a year later.
When it came time to release Dark Souls, FromSoftware self-published the game in Japan, but worked with Bandai Namco for a wider release in non-Japanese markets. That deal turned out to be huge for Bandai Namco. Dark Souls started printing money and Bandai Namco got a nice chunk of that profit. From was so satisfied with how Bandai Namco handled their end of the publishing deal that Dark Souls II and Dark Souls III were entirely published by Bandai Namco.
However, FromSoftware is an independent developer. That meant they were free to have their games published by whatever company they chose. That freedom allowed them to work with Sony to publish Bloodborne, a new IP that similarly sold incredibly well - but it sold incredibly well for From and Sony, Bandai Namco could only watch from the sidelines.
Project Vein looks very, very heavily inspired by Bloodborne. The promotional hashtag teased at the end of the trailer #PrepareToDine is even a slight variation on the original Dark Souls' catch phrase, "Prepare to die." I don't think that's a bad thing at all - some of the greatest works of art draw heavily from other works of art. However, I do think that at least some part of this Bandai Namco's decision to develop and self-publish Project Vein has to do with chasing after that sweet, sweet Bloodborne money - without having to rely on an independent developer like FromSoftware that could cut them out of future ventures.
Not only that, but Bandai Namco would actually own the Project Vein IP if it became successful. They would be free to adapt it to other mediums, much like what they did with their God Eater franchise. Interestingly, the same team that developed God Eater has now been shifted over to work on Project Vein. If you look at God Eater, there is a franchise that spans several games, several light novels, an anime series, and a trading card game, all of which have done relatively well. If Project Vein proves to be even half as popular as Bloodborne, it could be similarly adapted and serialized.
There's a lot of money on the line if Project Vein succeeds. Bandai Namco has tasted the success of Dark Souls and watched on as FromSoftware, the goose that was laying golden eggs for them, created another smashing success for Sony. A lot of this is speculation on my part, but Project Vein seems like Bandai Namco's attempt to cash in on the popularity of FromSoftware's mechanics and dark style. Here's hoping that this results in a great game that can live up to or surpass what inspired it and not a retaliatory cash grab.