I think it would be awesome to have pre-made animated/rigged Lotties that can then be applied to different, but similar SVG layers. My use case would be with many unique user-created SVG avatars on a site, which could then all be animated with the same motion using the same Lottie rig. This would give life to all the unique SVG avatars on the site at once, without having to go export them one-by-one in AE.
One way this might be accomplished is for Lottie to assign a label to animated shapes of an animation (probably close to the same way Lottie can change color of specific shapes) and allow new/different SVG layers to be attached to/replace those labeled rig components or "bones". So if a user were to build an avatar on our site (using similar parts but unique svg shapes), we could rig what they create with the Lottie "bones" to enable dynamically animated avatars outside of the AI -> AE flow.