They're not officially committed, no, but they're party establishment-types who have openly stated again and again they're supporting Clinton, and they have the cover to do so, when she's won over three million more votes than Sanders nationally.
The odds that they're going to abandon her in mass numbers at this point for Sanders is probably even lower than Bernie winning California with over 70% of the vote.
Not to mention, they’re probably scared to vote against the clinton crime syndicate. Better to take their chances with some pissed off young socialists.