He did.

But the meaning of “preemptive” is more like a “Just in case”, rather than, “immune from future offences”.

They were all pardoned from 2014 until now, but trump admin could theoretically invent a new case that allegedly happened on Jan 21 and make an investigstion out of it. (It probably wouldn’t go very far tho, I mean considering that even an indictment requires a majority of a grand jury to indict)