Is ASL mandatory for create release process ?

I've a doubt considering the scenario bellow

EBS Release 12.1.3

1-) Create a Blanket agreement for ITEM_XXX  ( BLANKET_1)

2-) Do not create ASL or Sourcing Rules

3-) In iProcurement search for TEM_XXX

4-) ITEM_XXX is already sourced from BLANKET_1 

5-) Approves the requisition.

6-)I workflow builder the AUTOCREATE_DOC attribute is set Y.  AUTO_APPROVE_DOC also set to Y.

7-) Buyer has authority to approve Blanket Releases

Since the requisition for ITEM_XXX is already sourced from  the BLANKET_1 . Shoudn't the release be automatically created ?

Why does the requisition still in buyer's pool ?

 Is ASL mandatory for create release process ?