Moving this issue from https://github.com/CesiumGS/cesium-ion-community/issues/179.
Right now Cesium ion supports tiling point clouds into 3D Tiles as LAS/LAZ. For an updated list of all the formats Cesium ion accepts, see: https://cesium.com/docs/tutorials/uploading/
A few users have requested the ability to upload point clouds as a CSV, with columns for X/Y/Z and optionally R/G/B, and other per-point metadata.
If this is a feature that you’d like to see, please comment or this post!