I can only see Shanks getting involved thoroughly in Wano if Luffy is unable to beat Kaido and gets KO'd or if Shanks' crew fully targets Big Mom's crew without interacting with the Straw Hats, the former of which I really don't see happening. Leaving aside the many elements of Luffy's arc Oda has screwed up since the timeskip, Shanks being dead-set on them not meeting until Luffy has proven himself a worthy rival is something he's kept consistent and all of Luffy's training amounting to him just softening up Kaido would go against that.
If he does get involved, I imagine it being perhaps through more of a support means or information relay linked to whatever was set up in the Reverie.