Is there a pre commitment for consuming Azure through CSP like EA ?

No. Azure through CSP is a monthly pay as you go consumption model and does not need a pre-committed consumption as part of the agreement. This flexibility allows partners to choose the right configuration of resources based on the current needs of the customer, instead of over provisioning any resources.

Quick and easy options to scale both horizontally and vertically fits well with the consumption model thus providing economies of scale and lower per month costs.

Remember that a customer can choose to have a subscription coming from EA simultaneously while consuming Azure through CSP as an additional subscription. Refer the FAQs further to understand how this works.