Accessibility features advocates flagged as being potentially dangerous will be removed from both the Tekken 8 demo (where the issue was identified) and in the full release of the game, apparently by launch on 26th January. Director Katushiro Harada said that "quite a bit" has been done to address concerns.
As reported by PC Gamer, Harada made the comments at the Tekken World Tour 2023 finals, speaking in the past tense, implying these changes should be present in the final version of the game. Harada claims the features were still being tweaked when the demo launched: "Many people have been talking about the accessibility features in the demo for Tekken 8. Actually, that was just a work in progress, so we've actually tweaked that quite a bit to try to address some of the issues and to make sure it works better for a wider variety of people."
It seems like something got lost along the way because the filter in question was supposed to help colourblind players, but instead, it reportedly made some feel sick with migraines and headaches, being more appropriate for players with low vision, anyway. The pattern used was similar to the infamous Porygon episode of Pokemon, and advocates raised concerns it could trigger cases of Sudden Unexpected Death in Epilepsy (SUDEP) when released to a worldwide audience.