Generally if you're using the term 'the gospel' in relation to something not the Bible you're making analogous comparison. If you look at the analogy then 'the gospel' in this context would be the law. Court precedence would actually be analogous to theological leaders and commentaries. They do carry some weight but they are not themselves 'the gospel'. They are the understanding of what 'the gospel' means and that understanding can change and is subject to review.

I do think it's a fair point to say that precedence should be reviewed in some circumstances to examine why they were set and if it was correctly set. We do not have an immutable constitution and we do not have an immutable set of laws, why would we think that court precedence all of a sudden become immutable for all of time?

There have been, in recent memory, rulings that have been brand new and are overarching. Oftentimes the precedents set prior only dealt with very specific and narrow issues that could be encompassed by this new ruling. The new ruling doesn't automatically invalidate those earlier ones but it does call into question if they are still valid.