I edited your post here to keep it relevant to the thread, but reached out to you directly for the other comments.
My apologies for the confusion. B2 is listed as in beta and read-only on the links page here: https://www.odrive.com/links/b2cloudstorage
I know this information can be missed, however, depending on your B2 linking flow.
Even though write is not currently support, the existing B2 support still provides a great deal of usefulness to some folks. We felt it was valuable enough to offer it in a read-only state, instead of not offering it at all.
Now that B2 has enhanced their integration capabilities, we will be adding the write ability once our new integration framework (in progress) is completed.