Timing to Make Transition to Responsive UI

Summary

Seeking an understanding of when responsive UI will be mandatory

Content

Hi-

Is there a known timing that customers are going to have to make a mandatory switch to the responsive UI? I know that new features and functionalities are rolling out constantly that are making more and more pages responsive UI enabled, but we are looking to understand the timing so we could schedule that activity at an opportune time that aligns with business activities.

Thanks,

Bernadette