I don't think it will be a nonchalant encounter, I'm sure it will be a world changing scene. Whenever the Poneglyphs are brought into the flashback story line, Lady Toki will take center stage. She will be one of the catalyst for Kaido returning to Wano.
Remember Momonosuke said that Kaido was the enemy of his parents, plural. The only reason Kaido would have a connection with Toki would be her involvement in the Void Century and her knowledge of the Poneglyphs.
The only question is if Oden met Toki before or after he traveled with Roger, honestly my bet is on before and that's what inspired him to open the borders of Wano in 20 years time, his travels with Roger just gave him the tools/knowledge he needed to do so, tools that Toki (for whatever reason) could not provide herself. Maybe in a similar vein to Robin's conversation with Rayleigh on Sabaody?