As part of the Digital Markets Act (DMA) evaluation [0], Apple was found to operate a market for headphones connected to its devices, while competing in the same market with own products and giving itself a competitive advantage by creating OS-features exclusive to them.
The EU found this is not a level playing field for competition and ordered that they have to make such OS features available for other accessory manufacturers as well.
I guess they are currently either trying to make a case for the EU on how it is technically impossible to provide the feature to others, prove that this is somehow not an OS-feature (and should be excluded) or delay any action to maximize the benefit of this competitive advantage in other markets.
I wouldn't be surprised if there are also beats headphones in the pipeline for which they want to use this feature as competitive USP...
[0] https://ec.europa.eu/commission/presscorner/detail/en/ip_25_...