Optimistic locking in B-Trees provides a method to manage concurrent access to data structures without using traditional locking mechanisms. It allows multiple transactions to proceed without acquiring locks, leading to potentially higher throughput in database operations. Key points include the nature of versioning in B-Trees, including questions about whether the version numbers are monotonically increasing, handling data type overflow (wrap arounds) as versions increment, and determining how versions are assigned to concurrent threads. This can affect both data integrity and performance, presenting challenges and opportunities for improvement in concurrent database access patterns.