Update by Miquel Ballester with some relevant new information:
Most significantly in my eyes:
Let’s hope that’s not just the silicone parts. {@UPPERCASErecently raised doubts whether a replacement individual earbud can be RE-paired with the remaining one at all.)
Other than that, the article specifies that the battery allows for 800 charging cycles. By the way, my own experience with its battery life is excellent so far. I think I only charged the case 3-4 times so far.