Not entirely without merit. But if you are talking about ford, the pardon was for what was certainly going to be a legal issue. Same for those pardoned in the civil war, who were guilty of treasonous acts.
In J6, the pardon came before any crimes had been alleged.
I go by the pardon power in the cotus, which would seem to indicate pardons are for crimes already committed...but..you are not wrong, there seems to be a precedent.
.granted, there are ways around that scheme..if those In charge would ever use them...