A Bloodborne update to reduce load times, improve performance, and squash bugs will arrive before the end of April, Sony has announced. Among other fixes, the 1.03 update will also resolve "an issue that resulted in abnormal game behavior after many continuous hours of play".
One of Bloodborne's few common criticisms (aside from it's really freaking hard) is that it takes a frustratingly long time to load the Hunter's Dream and other zones. Dying is supposed to be punished in Bloodborne, but sitting through multiple load screens of 30 seconds or more before you can even get back to the start of the area you perished in is apparently not meant to be one of death's many drawbacks.
The "abnormal game behavior" issue likely refers to a boss-nerfing bug that multiple players have independently observed. As it stands right now, leaving the game running for extended periods of time - the general consensus is about 12 hours - can significantly reduce the breadth of attacks that bosses use, making them unintentionally easy to beat. Using such a glitch to cheese your way through the game is, naturally, poor Bloodborne etiquette.
Sony says it will narrow down a more specific release date for Bloodborne's 1.03 patch soon.