It is pretty clear, that there will be no Synchronstage-dimensionstring Library, since the Microphoning-concept of both is simply not compatible. And I think there are already some statements like that by VSL-Guys.
I would expect that the Synchronstage-Libraries will "simply" replace the the former Core-Flagship the "Symphonic Cube". This is - however well done - already of some age and beside the new acoustic concept, there is a lot which might be improved from a nowaday point of view and available hardwarepower.
In so far the Cube includes Solostrings but no Appasionatastrings I would expect again a likewise basic set of sectionsizes from (Solo, Chamber, Orchestral) and presumably each section as 1. and 2. Version to cover the regular divisi needs. And yes I expect that the project to replace the former Core-Library with a Synchronstage version will absorbe defenitly some time.
However I fully consent that historic strings and at least a full set of Vowels (instead of only A+U) for The VSL-Choir and Soloists will be very very wellcome.