Last year an April Fool's joke suggesting the In & Out was adding bacon and avocado fooled a lot of people
This year - it's still working
From Eater:
As expected, In-N-Out has no announced plans to carry a larger food lineup any time soon. The restaurant chain is also and almost never does press of any kind, let alone influencer media events to try new dishes. The company even recently went so far as to against a pranking YouTuber who had been harassing customers and employees at several Southern California locations.
Sorry (also...April Fools Day is terrible)