Not at first, but at the moment, yes, it is intentional. We are working on migrating WebKit to a more permanent and complete Git repository, which involves editing history. Because of this, we didn’t want to further the confusion we already have with two different sets of git hashes. The new repository should be pushed in the next week or two

In the mean time, https://git.webkit.org/WebKit-https.git (secure, but different hashes than GitHub) and https://git.webkit.org/WebKit.git (uses the same hashes as GitHub), are up-to-date mirrors.

Jonathan