Maybe to try and help the parse? That’s usually the case when I see someone doing that. They are just not keen on the boss parsing rules.
Boss Changes
As always, all trash mobs are excluded from boss parsing. All Hard Modes rank higher than lower difficulties.
Example:
Player 1 does 3k DPS on Hodir HM. Player 2 does 4k DPS on Hodir non-HM. Player 1 ranks higher as every HM parse ranks higher by default.
Flame Leviathan
This boss is removed from character pages, All Star Points etc. It is still included in boss speed.
Ignis the Furnace Master
Only the killing blow on Iron Construct (ID: 33121) counts for damage parses.
Razorscale
Only Damage Done to Razorscale counts for parses, and Phase 1 is counted as Downtime.
XT-002 Deconstructor
Damage done to XM-024 Pummellers is excluded.
The Assembly of Iron
Damage done to boss mobs before they heal up to full is excluded.
Damage done during Overwhelming Power is normalized.
Kologarn
Damage done to Rubble is excluded.
Damage done to Left Arm and Right Arm only counts if they die.
Auriaya
Damage done to Swarming Guardian is excluded.
Hodir
There are no adjustments on this boss, all damage and adds count, but Hodir is removed from All Stars and Complete Raid.
Bringing Storm Power from Hodir to other bosses invalidates that boss kill + Complete Raids.
Thorim
Phase 1 is removed, and only damage done to Thorim counts. Using Aura of Celerity invalidates the rankings on the boss and the Complete Raid (Speed, Boss Fight, and Boss/Trash) rankings.
Freya
Damage done to Freya before her last overheal is excluded.
Mimiron
Downtime is removed during phase transitions.
General Vezax
On Hardmode only: Downtime and damage done between General Vezax reaching 5% health for the first time and Saronite Animus (ID: 33524) spawning is removed
Yogg-Saron
There are no adjustments on this boss, all damage and adds count. Overkill damage is obviously excluded, as that is excluded from everything by default.
Algalon
Damage done to Living Constellation, Dark Matter, and Unleashed Dark Matter is excluded.