So I ordered them as a precaution on 30.12., but they are already being delivered today. Good for me, but the whole thing is not really transparent.

Now it's 4-6 weeks, which is probably realistic.

On the Apple website, the delivery deadline is 31 January - for express delivery. Otherwise 3 February. It would be kind of crazy if Digitec had them in mid-January.
I don't actually need them until the end of January either, but just a few days earlier than 31.01.....

No one can tell you that. On the 24th it suddenly said 6-7 days. I ordered and now it says that they are expected to arrive at the supplier's today 🤷🏼♀️.