This article is making a big deal out of nothing, at least right now. The fact that Trump resumed doing non-presidential things doesn’t mean he believed that he lost the election, but only that he thought it was unlikely he’d be able to keep the White House.

Of course there could be specific legal positions that he can no longer reasonably advance because of his business decisions, but at the moment we don’t have any of those on hand.

Certainly this document doesn’t prove that he knew he lost anything. It simply shows what pragmatic steps he was taking.