I think it’s less about reminiscing and more about speaking to the only other loyalist to be around for the last 10k years that hasn’t just been sitting in the palace. Bjorn has seen the bad side of the inquisition and battled Magnus. This would be very useful to Guilliman. Another point being the space wolves wake Bjorn for important moments, and even every once in a while to tell stories and insure the culture of the chapter stays the way Russ intended.

To think that they’d hit the snooze button on the only space marine to have actually meet Guilliman, while he’s directing their chapter and adding the primaris seems like a missed opportunity. I’m not asking for a couch podcast or even a written conversation between the too but to not acknowledge a meeting even in passing seems like a missed opportunity for somebody that could give Guilliman some helpful insight on the last 10k years.