While I was working on the table, I found this article in FWW by Andrew Hunter about attaching tabletops this way.
https://www.finewoodworking.com/2010/06/03/better-way-to-attach-tabletops
In it, he writes:
This taper eliminates the precision needed to fit a straightcleat and the need for glue. With no glue, you can remove thebase from the top if needed, and if the fit of the cleat loosens due to wood movement, you can tap it back home or remove and shim it if necessary. I’ve never had to do either because I start off with very dry wood and use quartersawn lumber for the cleat.
Now that I look at it again, I realize that the quartersawn part is important -- the wood that I used is cherry, which apparently moves twice as much in tangential direction compared to the radial direction.
For now, I may shim it with wood shavings or paper and see how it holds up after another year of changing humidity.