Excel Javascript API: Question about Bindings

May consider a workaround as a combination of periodic checks and event listeners. 

Periodically Check for New Bindings: Use a timer to periodically check for new bindings in the workbook.

Add Event Listeners: Once a new binding is detected, add the necessary event listeners to it.

Code look like

async function checkForNewBindings() {
    await Excel.run(async (context) => {
        const bindings = context.workbook.bindings;
        bindings.load("items");
        await context.sync();
        
        bindings.items.forEach(binding => {
            if (!binding.onDataChanged) {
                binding.onDataChanged.add((...) => {
                    // Handle the data changed event
                });
            }
        });
    });
}

// Run the check periodically (e.g., every 5 seconds)
setInterval(checkForNewBindings, 5000);

This script will periodically check for new bindings and add the onDataChanged event listener to each new binding it finds.