So long as the copy is DRM-free, which I’m pretty certain Amazon and Apple are these days, there is no means to enforce such a revocation. Of course, you could find yourself unable to download a new copy should you ever need to.
I believe there have been instances where Amazon removed books from user Kindles, which (thought these files are indeed DRM'd), that is not the mechanism by which this was done.
"If I'm willing to violate the law I'm good" is true and I don't disagree, but that also applies to full-blown piracy.
