web.de is also a big email provider in Germany.

Yes and gmx (listed next to it) as well, and I’m pretty sure that gmx offered/offers multiples TLDs (gmx.net, gmx.de, gmx.at, …)

I think the same goes for Alice (big ISP, offering mail addresses, in multiple countries)

It looks like some of these wildcards are for mail providers who use multiple TLDs.