I’ve come to believe it was a mistake. As Tim Alberta pointed out, he didn’t really say anything new. And members that felt they needed distance from Trump had already felt free to establish it. All the call did was create more headlines about Republican dissension, make Ryan a hate figure for the Trump right, set Ryan up for the blame if Trump loses, and provoke Trump into pointlessly spending days attacking the speaker. None of this is helpful to anyone, especially to Ryan. All that said, the strategy of trying to save the House and spending all marginal dollars and energy on that makes sense. But it’s a strategy you can execute without declaring it publicly.
UPDATE–My apologies. I had missed Ramesh’s post earlier about this.