It's mostly just confirmation of something that we already knew.
Here's my recent post about their relationship before this update. The new part is that Ibaraki retrieves her arms by transforming into her own mother instead of Tsuna's.
Also, the new part about Tsuna not slaying Ibaraki because he likes seeing happiness on the face she inherited from her mother is the biggest possible follow-up for all the Hikaru Genji/Fujitsubo parallels in Tsuna's backstory. In The Tale of Genji, Hikaru quickly accepted that he couldn't have Fujitsubo, so he groomed the child who inherited Fujitsubo's face, Murasaki no Ue, who eventually became Hikaru's endgame main wife. We could have done without taking the reference this far, but it is what it is.