I was half-joking. You're right that it probably wouldn't pass.
But politically, it's the only way I can see them possibly both technically keeping their promise and not causing themselves a catastrophe.
I think it's quite possible that no plan is actually able to pass in the end, and so current law remains intact. Remember that while they can defund the current law with 50 votes in the Senate plus a majority in the House, they can't actually change insurance regulations without being subject to a Democratic filibuster, and good luck with that.
So Trump and others insist on it being "repeal and replace" rather than just "repeal and nothing", but they can't actually get the votes to pass their "replace" option, so nothing passes, and Trump tries to blame the Dems for thwarting his election promise.
But do they really think defunding the law will make people think it's the Democrats fault for the ACA's failure?