This is a legitimate point and maybe they should be saying those things, but where do you go with those questions? Is raising them going to be particularly damaging? Probably not, because those questions have been out there a long time. People interested in connecting those dots connected them a long time ago. There's an overriding "why" IMO - why is Trump talking about burying the report? Withholding its findings not just from the American public, but from Congress?
Republican senators might have a good reason for not playing along with such a White House attempt. They stand to be completely blindsided by what the damn thing actually says. In principle, they might be willing to go along with a coverup, but wouldn't they want to know the dimensions of what's being covered up, if only to assess the political damage they may be exposing themselves to?
I doubt if the pounding away of Trump talking points is going to win Trump any new converts. Meanwhile, though I don't necessarily trust Lindsey Graham to do the right thing, I do trust that he has an instinct for self-preservation. So there's that.