It is morally wrong to conceive eight embryos and freeze seven. The only truly moral way to do artificial insemination is to try the process one embryo conceived at a time, or implant all conceived embryos and try to bring them to natural birth. You might even line up several ‘mothers’/surrogates so no conceived embryo is ‘frozen like processed fish’.
The Church insists that ALL such implantations are gravely immoral - even when done purely out of compassion for the frozen embryos.
It is morally wrong to create any embryos except the natural way. It is morally wrong to remove any embryos from the mother.
In other words: artificial insemination is always immoral.