Oh no, once the FBI does any investigation they will then demand hearings to give testimony before them.
What if the FBI refuses to investigate? I am sure the calls went out today, to Trump and they are talking about it now. A scenario not many have discussed. The three Senators on the fence really are not but are requesting this, the FBI refuses or says not enough evidence to investigate, McConnell asks for the vote and they vote Yes. That is a very plausible scenario