I don’t know whether this approach means that the user must also click Save at the bottom of the New Login pop-up to save the new credentials, or if this will only be required if any changes are made on the New Login page after it has popped up. If the former, could potentially cause some issues with lost credentials. 
I actually found this change among the updates that were included in the release of version 2025.5.0 (which is already available). This could mean that Bitwarden is temporarily controlling the availability of the feature using a so-called “feature flag” (the value of which is set on Bitwarden’s cloud server). If this is the case, Bitwarden has the ability to immediately make the feature available at any time, simply by changing the value of the feature flag on their end; however, they obviously have a reason to withhold the feature for now, and there is no way for us to know what Bitwarden’s plans are with regards to when the feature will be activated (unless someone on the inside can shed some light — perhaps @dwbit?)