Hide "Recently Ordered" blocks

You can disable recently order in admin. 

Refer below steps to enable or disable customer reorder in Magento 2: 

• On the Admin panel, click Stores. 
• In the Settings section, select Configuration. 
• Select Sales under Sales in the panel on the left Open the Reorder section 
• In the Allow Reorder field, select Yes to allow reorders and select No to disable reorders. 
• When complete, click Save.

Note: By default this option is set to no. Set it to yes and clear any caches to see the results.