Does the free Spotlight trial subscription end automatically?

Yes. The free trial period for your Spotlight Add-On ends automatically. You do not need to cancel it. 

Also: After the free trial period, your Spotlight profile and the data transferred via Filmmakers to Spotlight will be automatically deleted, unless you actively decide to keep the Spotlight Add-On.

Before the trial period ends, Filmmakers will send you an email informing you that you can subscribe to the Spotlight Add-On for a fee. The subscription does not happen automatically; it only occurs if you actively choose it.