FBI Director Christopher Wray told lawmakers Thursday he could not “lawfully†give them access to a confidential warrant application for permission to surveil members of the Trump campaign, but President Donald Trump could lawfully order him to do just that through his subordinates at the FBI and Department of Justice (DOJ).
A risky move. It's possible such an order may turn up unexpected sources of evidence, besides the discredited dossier. The press would party for a whole seek if that happened. Trump may be better off to let people think it all came from the dossier and let the FBI twist in the wind.
Since the Press could just make stuff up as it goes along this is a very real possibility.