Removing the lock icon is a very good idea. I’m not surprised that Chrome’s team found out that only 11% of participants to a survey understood what it really means.
not only is removing the lock icon a good idea, replacing it with a dropdown indicator is a great idea. there's all kinds of useful stuff in that menu, currently hidden behind something that looks like a status indicator rather than an interactive element.
That means they should wait until 90% of them know what it means, before removing it.