To put it rather simply, outside of the Trump administration, the DOJ isn’t there to do the president’s political bidding and the president does not call on the DOJ to do its political bidding. Moreover, the president and the DOJ are typically not coordinating with regard to specific cases. That is, the DOJ is not reporting to the president any details on cases that don’t involve issues of national security. I think it’s safe to assume that Biden and Garland (or other folks who are high up in the DOJ) didn’t discuss the Epstein case.