While true, in universe the Space Wolves don't really like the newer guys, because they aren't from Fenris.
From the outside in, it is a useless hazing, but for them it's tradition.
A theme being used more often in 40k stories is challenging tradition, with battling varying levels of success.

actual primaris scale wolf nauts, that'll be the day

just gotta thank Curze for the mental illness

They're gonna go bonkers, and Bjorn will go, "Yeah that makes sense."

Corax is probably a raven demon of Big E killing in the Warp, and Khan is in the Webway, not having the time of his life with the Dark Eldar

Still waiting on a Joytoy Heresy figure of Russ.
He gets in 40k, we'll have two Primarchs with elf gfs

Primaris are new versions of Space Marines. taller, faster, stronger, made on Mars under supervision of Belasarius Cawl from the Mechanicum.
can't wait to see your reaction to Guilliman and Johnson being back

Murderfang is in one hell of a wheelchair, then

That is described in the first Ragnar book. They do it to newer Primaris Marines as well, iirc. Makes them more like the Vylka Fenryka that came before them.

Brand new Space Wolves start as Blood Claws, where Wolf Scouts have lost most of their original squad/pack and act as solo operatives. Been a thing since 5th edition.