Consider a hub-and-spoke topology, where spoke VNs are exporting their routes with RT-1 and importing only hub VN routes via RT-2. Now, if one of spoke VNs is connected to a LR, because the snat RI is copying the spoke VNs import-only RT into its import-list, the default static route will be advertised with RT-2. As such, this route will be imported by all the spoke VNs, even though they aren't connected to a LR.
Consider a hub-and-spoke topology, where spoke VNs are exporting their routes with RT-1 and importing only hub VN routes via RT-2. Now, if one of spoke VNs is connected to a LR, because the snat RI is copying the spoke VNs import-only RT into its import-list, the default static route will be advertised with RT-2. As such, this route will be imported by all the spoke VNs, even though they aren't connected to a LR.