The article describes the NYT's explicit decision to reject objectivity and engage in active advocacy. That's not a "slip"
If you believe they're "less biased", it's likely because you agree with a) their approach or b) their goals.
Either way, it translates to "bias is fine as long as I agree with it" which IS the major thesis of the entire post-journalism analysis.
We can tell whichever shade of grey that we want to tell that those who are listening to us what to hear in the frame and the rhetoric which appeals to them. Fox news is biased to tell the partial truth of a certain demographic which feels empowered by that rhetoric. If more people believe reality as told by Fox News it gives them more power within the system to get whatever they think it is that they want. Currently they are going after Cuomo, a democrat, in the sidebars there are criticisms of cancel culture.