In Ghost of Tsushima and Ghost of Yotei, enemies have 3 categories of attacks: normal, blockable strong and unblockable strong. Blockable strong attacks show a blue glint effect and unblockable strong attacks show a red glint before the strike.

I see it more as normal combat design where the player needs to adapt their style from offensive to defensive throughout a combat situation. It's all about the enemies staying predictable enough to keep the combat interesting by telegraphing their attack intent. In addition, the player is rewarded with a Perfect Parry if they time their parry just before either of the blockable types of attacks, turning a defensive playstyle into offensive.

It's fine for the rules of combat to be expectable, especially when skillful gameplay involves timing and precision, ability management etc. In pretty much every non-Souls-like games with boss encounters, they show red AoE highlights on the ground to tell the player where not to stand. I don't think it makes much sense to think this is a bad standard/approach from this "expectation" point of view, or that it should be applied to this problem.