Minecraft wiki entry for Development_versions, associated text: MC-173207 – Bullseye advancement can be made when using a non-arrow projectile, even though the description explicitly mentions arrows.
MC-173756 – Ice Bucket Challenge advancement can be obtained by collecting obsidian from bartering.
MC-175992 – Striders are not part of the "Two by Two" advancement challenge.
MC-179481 – Structure block offset cannot be bigger than 32.
MC-181482 – Dying while riding an entity respawns the player next to that entity if the gamerule doImmediateRespawn is true.