Blizzard has posted new Dragonflight hotfix notes, buffing Heroic Fyrakk due to concerns that the final boss of Amirdrassil was not challenging enough, and restricting addons from checking distance. This second vague note under the User Interface section is actually a substantial change, which affects the ability for popular addons like Deadly Boss Mods, Big Wigs, and Weak Auras from using Range Radars or other forms of checking distance between them and another player — very useful tools when trying to spread out for specific mechanics, and could result in a significant difficulty spike in some content.
Even raid frames will no longer show when players are out of range, which can be of particular importance to tanks and healers.
Example of DBM's range radar tech, which allowed players how close they were to one another, a function which no longer works as of today's hotfixes.
Please keep in mind that some issues cannot be addressed without a client-side patch update. This list will be updated as additional hotfixes are applied.