Yes, the Magento 2 eBay Connector module sends tracking information back to eBay for the imported orders. When the admin process the shipments in Magento, the tracking information is automatically synchronized to the corresponding eBay order in real-time. But vice versa is not possible.
Note: This feature is not supported in the sandbox account. This feature can be implemented or tested in the live account only.
Please do contact us for any further queries or requirements. You can also check our magento2 Extensions for additional features.