“fewer than 0.02% of requests made to the Git backend come through a Subversion endpoint, and only about 5,000 repositories see even a single Subversion request each month.”
GitHub turns off Subversion support on January 8, 2024, with brownouts late in 2023. The bridge existed to coax centralized shops onto Git, and that job finished years ago. About 5,000 repositories still touch it monthly. Those users are the ones who will find out from a failed checkout during a brownout.