No. Sanders proxies on the #UnityReformCommission were the most vocal in defense of the caucuses. But most of them ended up voting (unanimously) with the rest of the commission on the changes.
https://frontloading.blogspot.com/2017/12/unity-reform-commission-caucuses.html https://twitter.com/huzzahmpls/status/1247930553254522882

Had this thread on the same subject last month. https://twitter.com/FHQ/status/1237734687294074881