Add note about SP being required in the future (#6799)

* Add note about SP

* Update nservicebus/usage/index.md

Co-authored-by: Andreas Bednarz <[email protected]>

* Update nservicebus/usage/index.md

---------

Co-authored-by: Andreas Bednarz <[email protected]>

Author: jpalac

nservicebus/usage/index.md

@@ -26,15 +26,18 @@ The recommended method for measuring usage in an NServiceBus system is via Servi
 
 This method requires ServicePulse version 1.40 or later, and ServiceControl version 5.4 or later. Additionally, if using RabbitMQ broker, version 3.10.0 or higher is required.
 
-To learn more about this method, read the [ServicePulse Usage documentation](/servicepulse/usage.md). 
+To learn more about this method, read the [ServicePulse Usage documentation](/servicepulse/usage.md).
+
+> [!NOTE]
+> While customers are not required to use ServicePulse at this time, it will become a requirement for all active projects in the future.
 
 ## Standalone Endpoint Throughput tool
 
 Customers who are not able to use ServicePulse can use the Endpoint Throughput tool to measure their system usage.
 
 This is a standalone tool that is run on demand, and can typically be installed on a [user's workstation](/nservicebus/throughput-tool/faq.md#does-the-tool-need-to-run-on-my-production-server).
 
-To learn more about this method, read the [Endpoint Throughput tool documentation](./../throughput-tool). 
+To learn more about this method, read the [Endpoint Throughput tool documentation](./../throughput-tool).
 
 ## Requirements