No, they aren't going to publish the SAT Subject Test papers officially because they already released the Subject Tests in the form of practice books.
You're not going to get any SAT Subject Test sample papers online for free. But I suggest you a prep company where you'll find the solutions of 4 Math, 2 Physics and 2 Chemistry tests. These 8 sample papers are alike the College Board's sample ones.
Check the [url=https://www.testprepkart.com/campaign/sat-test-series-&-solutions.php]SAT Subject Test sample papers[/url] to buy the 8 practice papers.