I think Roddy was speculating on this. 94.5 is only licensed to simulcast, so the owner has to LMA 94.1 HD3 from LFM in order to launch a new format.
That would be true if a separate entity was LMAing 94.5. They would need a main signal to "translate." But if 790 used the translator, they would not need an HD signal to duplicate; they would just duplicate 790 AM.