Hey Folks, I want to write this post in order to list out my hopes and thoughts as well as get some of your ideas for raid bosses.
My opinion is only semi-informed as I haven't read and watched everything to do with ashes, but I will go off of what I think is right.
As far as I've heard there will be no open API for Ashes and therefore no addons will be made for the game. The reasoning I heard for this was that the developers want to create a game that is customizable and listen to their player base in order to make changes and constantly improve the game, themselves without making the players rely on third party addons. I have also heard that bosses won't simply show what abilities they are using/casting at any given moment, and there won't be any given marks to players to move to, how to dodge those mechanics, or when to interrupt them etc. etc. I also understand that the developers want to create a system where bosses adjust their difficulty and loot table based on the players performance of the previous boss. This involves the boss not only getting stronger and having a higher health pool, but also learning and using new mechanics on the raid group.
So, as players we would want to be able to prepare for these boss fights, and devise plans in order to defeat them. In a lot of other games, mechanics of bosses are usually just listed on a database such as WoWHead for World of Warcraft and FFXIV Wiki for Final Fantasy XIV.
That got me thinking, if a bosses mechanics are influenced by the raids performance then and AOC database or wiki could be unreliable. I started thinking about how this issue could be solved -
(If this even is an issue and I'm not overthinking it)
I thought a very cool way to prepare for boss mechanics is literally in game. The same way rogues will be able to find hidden passage ways and treasures, there should be some sort of way the players can analyze the boss for its mechanics. I don't think it would be a good idea to run in, gung-ho, wipe and learn the mechanics by trial and error. It would be a lot more interesting if different classes or professions or someone with a certain skillset can analyze that boss in order to inform the raid group and create a plan together.

For example: Mages would be able to understand some elemental abilities the boss has, clerics could understand necrotic abilities or holy mechanics, rogues/fighters would be able to figure out the physical mechanics, etc
In summary, I think it would be really cool for players to analyze bosses with different results and keep everything in game without having to break immersion and having to go on a website or a database,
as well as providing different classes or professions a little bit more utility inside the raid, bringing the raid team closer together.