If they don't release a Comedy Comics Masterworks, they could always put the "serious" material from those issues in the Rarities volume.  I don't think Cory would overlook them.  The proposed Comedy/Daring volume 3 personally doesn't make sense to me.  There were several years gap between those two series and they are really not related.  Thematically, the new Daring are much closer to the final issues of USA than Comedy Comics as both are from late 44-45.  Note, I would also question the "serious" distinction you make.  You do realize we are all talking about comics that were essentially made for children right?