Battery Replacement - iPhone X

Hi, I went to the Apple Store with an appointment for a battery replacement on my iPhone X and was told that they couldn’t change my battery because they didn’t have any speakers left in stock. Have I been fooled? Or is it really necessary to change the speaker as well when we want to replace the battery on an iPhone X? Also, the genius said I would be contacted when the piece arrives but he didn’t ask me to confirm any number/mail adresse and haven’t received anything by email from my visit as I usually do? Has anyone had such an experience? Why do they have to replace a perfectly working speaker when replacing a battery? I’m so confused.