Here's some past history:
HM+BRF - Same ilvl
HFC - Staggered in 4 increments, Archi higher ilvl
EN - Same ilvl
ToV - Helya higher ilvl
NH - Staggered in 3 increments, Guldan higher ilvl
KJ - KJ higher ilvl
ATBT - Argus higher ilvl
> Uldir - Same ilvl
> BoD - Same ilvl
[ future: CoS - Uu'nat 5 ilvls higher than Cabal ]
edit: Mod can edit in the word 'have' for readability. Don't see an edit thread title option.
edit 2: For further clarity, poll question is in regards to the rest of the instance. Aka, should G'huun have dropped higher than 385 base, and Jaina higher than 415 base in their respective mythic difficulties?