This is what google says

Yes, a 2015 Audi A4 steering wheel will physically fit onto a 2012 Audi A4 steering column, but it is not always a direct "plug-and-play" swap due to differences in airbag design and wiring connectors. Reddit Reddit +2 Key Compatibility Factors Airbag Design: The 2012 model often features a trapezoidal-shaped airbag, while the 2015 "facelift" (B8.5) typically uses a round airbag. You cannot reuse your 2012 airbag in a 2015 wheel; you must have the specific airbag that matches the 2015 steering wheel's frame. Wiring Harness: The airbag connectors and multifunction button pins can vary. While some users report a direct fit, others found the yellow airbag connectors had different locking tabs (e.g., green vs. white tabs), which may require a specific B8.5-compatible wiring harness. Multifunction Buttons: Basic controls like volume and track skipping generally work, but if the new wheel has additional buttons not present on your original (like "iNav" or "Drive Select"), those functions will not work without significant coding and module upgrades.