I gave a poor answer earlier. I was thinking of a different situation. I apologize.
But the main issue here, with the precise locks and limits you're using, is that 3D angles aren't decomposable into 3 independent axes.
The easiest example of this is to consider two different XYZ Euler triplets: either rotate in x by 180 degrees; or rotate in Y then Z 180 degrees each. This is the exact same orientation. So when we look at this orientation, does it have Y axis rotation? When we lock an IK bone in Y, should this be an orientation it should be able to reach?
Let's do an experiment. Just take one bone, make it any kind of Euler we want, and then rotate it in only local X and Z axes. For ZX Eulers, rotating it in X then Z will give us Y axis rotation; for XZ Eulers, rotating it in Z then X will give us Y axis rotation. Even though we never rotated it in Y! So do those orientations have Y axis rotation? Are these orientations that a Y-locked IK bone should reach? No matter what the orientation, our Y locked IK bone is going to have Y axis rotation when it rotates in both X and Z, because the Y is not independent of X and Z.
Let's do another experiment. Let's make a Y locked IK bone, a bone that locked tracks X then Z the target, a bone that locked tracks Z then X the target, and a bone that damped tracks the target, and rather than looking at their Y channel values in some particular Euler order, let's look at what direction their axes are pointing:
We can only see three bones there-- that's because the Y-locked IK bone has the exact same orientation as the damped tracking bone. Meanwhile, the two locked track bones' axes point completely different directions. The IK bone and the damped track bones' "roll" are in the middle of our two locked track orientations. That's how a Y-only locked IK bone acts; and this is indeed the smartest way it could act. The concept of bone twist is not as intuitive as it first seems, because it is not independent of other rotation, but this is the closest we can get to the idea of no-twist.
Now, what you're showing here is an upper arm, with an upper arm twist bone, and an IK forearm, presumably with a 3-bone chain length. There is likely one of two practical questions here that you want answered:
How to keep the upper arm from adopting ugly positions? The answer is not through IK angle limits, but through restraining yourself from placing the IK target in places that will lead to ugly positions. There are places where an arm cannot reach. Don't put the IK target there. Trying to enforce arm position via IK angle limits will lead to twitch if it ever comes into play. A good upper + lower arm IK system has 1 and only 1 solution for any position of the IK target (within reach), which is exactly what you want for IK, and all angle limits can do is make situations where there is no solution, so the bones will do something weird.
How to make a automatic twist bone setup for IK? Start with a two-bone IK arm (upper arm, forearm) without any angle limits on any bone, with the forearm slightly, naturally bent. Disable deform on the upper arm bone. Create a new upper arm, parented to shoulder, and damped track the tail of the IK upper arm. Create an upper arm twist bone and parent it to the IK upper arm: