Since the champion's release, Yoru, with his design has had an opportunity to be a fan favorite. His performance, on the other hand, has been found lacking and Riot are aiming to get it fixed as soon as possible.
Japanese native Yoru rips holes straight through reality to infiltrate enemy lines unseen. Using deception and aggression in equal measure, he gets the drop on each target before they know where to look.
However, for all his edginess, Your has not had a good time in the game, and his performance has been lacking compared to other agents, especially those of a similar kit and role.
For that reason, Riot are intending to buff him as soon as possible, with the current date planned to be patch 4.03, as stated in a recent Twitter leak. Patch 4.03, along with the intended Yoru buffs, is coming February 08-09, 2022, depending on your region.
However, this is still TBD, meaning that there's a very good chance that this pushes out another patch to 4.04, pending on bugs/clarity/prioritization. In general, developers, as one says on Reddit like to lean towards transparency when they can, but that also can generate additional confusion or frustration when those timelines don't pan out as they had hoped.
At this point, the big takeaway we can take from this is "Yoru changes won't launch during patch 4.01 or 4.02, but developers are trying to get them out ASAP." Patch 4.03 is aspirational, but Act 2, 4.04, is still probably more realistic, unfortunately.