Hi, and welcome to OpenStreetMap! Since you requested a review, I looked over your changes here. Looks great! I'm not sure what specifically the warning you got was, but I didn't see any real problems with your addition. Here are some possibilities though... (none of these apply here, as far as I can tell)

- "Routable features" like foot paths, roads, etc. should generally be connected to one another to be useful. That means a "floating" feature or group of features isn't very useful for routing.
- If features overlap or cross: They should either be connected in real life like a crossing across a road, or they should be tagged as tunnel/bridge etc. as appropriate.

Let me know if you have any questions, and thanks for your contributions!