Not everything
I mostly following here only SM-Liiga, KHL and SEL.
Just before Forsling goes to U20, he was played with Linköping captain Magnus Johansson in their 2:nd d-pair. AHL returnee Mattias Bäckman take Forsling's spot with Johansson when Gustav left team. I think because Bäckman return, LHC give experienced Slovakia World Championship d-men Granak to Friboug. Melin seems happy Bäckman-Johansson pair at this moment, so this make it harder for Forsling, unfortunately.
Bäckman didn't succesful at all in Grand Rapids and he was frustrated for his ice-time, but he is a good d-men in SHL gamestyle and bigger ice. In SEL he has been EHT-level d-man. At this moment it seems that Gustav come to play rest of this year regular season in their 3:rd d-pair, but there's still little hope that Forsling can take that top4-role.