Is there any hint of problems to come in EB white's commentary on idyllic three-generation family relationships in once More to the lake?

Yes, in E.B. White's "Once More to the Lake," there are hints of the passage of time and the inevitability of change. The narrator's nostalgic return to the lake with his son underscores the passing of generations and the contrast between the past and present. This reflection suggests a sense of loss and the realization that some things may never be the same.