are raids harder in onyxia than in original vanilla?

now that the raids are 25 man are all the original 40 man bosses nerfed to have less health and deal less damage or are they the same? and if they are nerfed how much less damage and health do they have? does it make it harder or easier than original vanilla?

majority of bosses yes, the ones who aren't nerfed are ragna/nefarian last i checked and both are still very doable.
does it make it harder? for pugs yeah it can be. but the raids can be easy from a raiding guild standpoint, primarily due to coordination, but even top guilds on server still wipe on chromagus/firemaw/ebonroc/flamegor, and recent timer changes made some mc bosses alot harder than they used to be
if you find a guild to raid with, onyxia is one of the most enjoyable and well tuned servers to ever exist. raids are not overtuned and QoL exists to make the experience better.