Although The Simpsons has never been consistent with one supporting character’s personal journey, the show used this to its advantage in season 36. The Simpsons is, at the very least, consistent in its inconsistency. The long-running series has changed the main character’s ages countless times, retconned basic story elements like where the family lives and the existence of some supporting stars, and never prioritized keeping its canon clear. To quote current showrunner Matt Selman (via X, formerly Twitter), The Simpsons has an “Elastic” canon wherein every element of the show’s reality can change without warning in service of a gag.

https://screenrant.com/simpsons-season-36-barney-sobriety-continuity-canon-change-explainer/