The useful shift is automation at the CDN-to-origin boundary: operators no longer need to manually force post-quantum key exchange, while Cloudflare says its measured HelloRetryRequest rate fell from about 52% to 3.7% across the scanned cohort.
The technical migration is unchanged, but Reddit's documentation has proven unusually volatile. Integrations should now treat September 21 as the current objective/form readiness date and December 8 as the current published cutoff for HOUR reports longer than seven days—while continuing to recheck the live docs before each deadline.
The endpoint names are staying the same, but the trust chain is not. Teams that pin Sentry certificates or still ship very old Android/Java runtimes need to remove or update those assumptions before Sentry publishes its exact February cutover date.