The recent update to the gem building process ensures that only gemspec pushes containing a bumped version will trigger a rebuild, addressing the issue of accidentally overwriting a good gem release with a faulty development version. Previously, any modified gemspec would be rebuilt automatically, posing a risk to the integrity of stable versions. While this change guarantees the immutability of specific gem versions once released, it requires developers to increment the version number if they need to correct a release mistake. This trade-off is considered worthwhile to maintain the reliability of gem releases, as articulated by Tom Preston-Werner.