I admittedly don't know enough about the underlying cryptography to have an educated opinion, but it seems like they put some due diligence into determining it still provided value.
1Password uses TLS, and SRP inside TLS. If TLS is broken as in Cloudbleed, SRP hopefully still protects the channel - at least against non-active attacks such as Cloudbleed. The security still ultimately relies on TLS. Having not read the document fully, I think those would be against initial registration or in an active MITM allowing password-guessing. I'm looking at page 52 of https://1password.com/teams/white-paper/1Password%20for%20Te....