Primary Key index with Include

As you know version 11 gives us the possibility to include aditional columns
to an index.
So, if I recreate all my primary key indexes to contain a description
column, like ...

CREATE UNIQUE INDEX CONCURRENTLY Products_pk ON Products(Product_ID)
INCLUDE(Name);
ALTER TABLE Products ADD CONSTRAINT Products_pk PRIMARY KEY(Product_ID)
USING INDEX Products_pk

Then, when I do
select Item_ID, Product_ID, Name from Items inner join Products
using(Product_ID)

I thought It would do a index scan only for Products table, but it does not,
why ?
What do I need do to use index scan only when searching Product_ID and Name
on table Products ?

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