Migrating Oracle Views to SQL Server
Option 1

The correct answer is:

git export


In other words, the DDLs should exist in a code repository.

Option 2

Second option, use SQL*Developer's cart feature.

You can drag+drop the VIEWS of interest and export out all of the DDLs at once.

Option 3

I believe the cart feature uses DBMS_METADATA.GET_DDL() behind the scenes.

You'd have to roll your own code that loops through all of the relevant VIEWS.

Alternatives


  The fastest way to do something is to not do it at all
  
  -- Thomas Kyte


In this case:  Don't migrate off of Oracle.

Most Oracle licenses are bought on a perpetual basis.  You can run Oracle until the end of time, you just can't upgrade/patch it after you stop paying "maintenance and support".

I would have upgraded the database to 18c (latest) and stop paying the "maintenance and support".

"long term access" would still be a problem.  I would at least investigate if 18c XE (not yet out) can accommodate all of the static data.  It is supposed to include Advance Compression.

Final Thoughts

Since you said this is for READ ONLY archive purpose, I'll only remind you: 
 "Database agnostic code is a myth".