I had not tested building an agl-demo-platform image with the agl-demo-preload feature enabled when upgrading to thud, as it had seemed that the navigation app was being replaced.  Since the old navigation app is currently still being used (perhaps in error), and it seems that the POI app will remain in use with its replacement(s), I tried a build to test a fix to the navigation app for SPEC-2557, and discovered it fails with:

WARNING: agl-demo-platform-1.0-r0 do_rootfs: Manifest /ws/scottm/dev/agl/agl-repo/build-i7/tmp/sstate-control/manifest-x86_64_x86_64-nativesdk-poiapp-api-key.package_write_rpm not found in intel_corei7_64 corei7-64-intel-common corei7-64 core2-64 x86_64 allarch x86_64_x86_64-nativesdk (variant '')?
ERROR: agl-demo-platform-1.0-r0 do_rootfs: No manifest generated from: poiapp-api-key in /ws/scottm/dev/agl/agl-repo/meta-agl-demo/recipes-demo-hmi/navigation/poiapp-api-key_1.0.bb
ERROR: agl-demo-platform-1.0-r0 do_rootfs: Function failed: do_rootfs
ERROR: Logfile of failure stored in: /ws/scottm/dev/agl/agl-repo/build-i7/tmp/work/intel_corei7_64-agl-linux/agl-demo-platform/1.0-r0/temp/log.do_rootfs.32747
ERROR: Task (/ws/scottm/dev/agl/agl-repo/meta-agl-demo/recipes-platform/images/agl-demo-platform.bb:do_rootfs) failed with exit code '1'

This seems to be due to a change somewhere in rootfs construction between rocko and thud.