I tend to agree with you that Trump doesn’t spend much time thinking about abortion, but you know what he does spend a lot of time thinking about? How his base feels about him, which makes him a refreshing departure from the previous 2 Republican presidents.
Trump's base is not monolithically anti-abortion. In fact, I'd be willing to bet that if you polled only those people who supported candidate Donald Trump in the primaries, you'd find that abortion consistently ranked near the bottom of issues they cared deeply about.