These articles are trigger bait, nothing more. Biden is not going to order his DOJ to investigate Trump, which would be highly controversial with Senate Republicans, who he will need votes from. It would also further erode the line between the DOJ and the presidency. There is also a strong chance Trump pardons himself and his family, which would nullify any federal prosecution anyway.
Biden wants prosecutors to act independently. Notably, independently includes sharing information with the NY AG if so requested. Such requests haven’t been facilitated by Barr, to say the least.
Finally, it would be stupid for Biden to say he’s going to order the DOJ to investigate Trump. He hasn’t taken office yet and there is a slap-dash public relations and legal gambit to make sure he never does. If he announces investigations, that might push Republican legislatures to act.