No one says Spiegel…Ei. if I say Kund:innen like that everyone will just hear Kundinnen.
And I also don’t think people will get used to it. When something new gets introduced into a language, the first natural thing is to adjust it to the speaking pattern. Which is not possible here as it is an explicit and intentional break of the speaking pattern. It will stay alien as it pretty much intents to stay alien.
Maybe children that are just learning to speak atm will, but current adults? Only those who want to really really convince themselves for ideological reasons.
As a German, I’m pretty sure they’re right. Look into glottal stop, it’s not really a long pause or anything. Think of the difference of the connection of “Spiegel” and “ei” in Spiegelei, and “Schreiner” and “ei” in Schreinerei. It’s this short contraction that stops airflow and then releases it again, and it’s present at the beginning of the “ei” in Spiegelei, but not in Schreinerei.
Here’s also the IPA pronunciations from Wiktionary:
Spiegelei: [ˈʃpiːɡl̩ˌʔaɪ̯]
Schreinerei: [ʃʁaɪ̯nəˈʁaɪ̯]
ʔ is the symbol for the glottal stop: https://en.m.wikipedia.org/wiki/Glottal_stop
As I said, it’s barely noticeable but you do make a stop in between. You’re just used to using the word in your daily vocabulary that you don’t notice it. And as mentioned before, if you care enough, you’ll do it - if you don’t, you won’t. A little close-minded if you ask me but that’s just my two cents. :)
