There was an interesting story from Pia Leweling last night. From this story you can read which players are currently in the course at the Olympic base in Heidelberg. I'm assuming that this is about the U23 course, even if Vital Heynen and not Nicki Neubauer is marked.
OPP: Lena Große Scharmann (1998), Liza Kastrup (1999), Lydia Stemmler (2001)
OH: Pia Leweling (1998), Luisa Keller (2001), Sina Stöckmann (2002)
L: Annie Cesar (1997), Elisa Lohmann (1998), Sophie Dreblow (1998)
The name Annie Cesar in particular surprises me. But I also see the possibility here that it is also a tactical move by Vital Heynen, who wants to find out who he nominates for the senior team as the second Libera behind Anna Pogany as the second Libera. There is a lot to choose from with Annie Cesar, Elisa Lohmann, Linda Bock and Sophie Dreblow.
Edit: Lydia Stemmler is also linked in a story by Liza Kastrup, which is why I added her.