Yes, I think it's right that Slott should have Ben and Johnny's coming to terms of life without the rest of the family happen in these pages and not just in the pages of 2-in1.
D'Zarsky has done fine work in that book but this has to be a proper part of Slott's story too and the emotional journey that Ben and Johnny have been on shouldn't just be footnoted here as "See recent issues of Marvel 2-in-1".
In some ways, this could have been labeled a #0 issue, one that sets the stage for the real #1 but I don't think that was necessary.
If this opening arc is about bringing the family back together, this issue, in every way, earns the right to be considered a proper #1.