We have been using FCBEditor (managed solution provided by Microsoft support team) to set FCB.FormFieldDescriptions to true so that 'field description' is displayed below 'field label' in the main forms.

See screenshot of Field description displayed in the Contact entity main form: https://1drv.ms/i/s!AqINPhMvGkY7oQv2U1H4nsaoOBLC?e=Ea3RTU

But after the new UI (released on PowerApp 2024 Wave 2) is enabled, 'field description' is not displayed in the main-form of entity in Model-driven app.

See screenshot of Field description is not displayed in the Contact entity main form: https://1drv.ms/i/s!AqINPhMvGkY7oQpn052DOrkKzcHu?e=VkmJa7

The field description is used in our major systems that has with more than 1000 users. The field description is widely used by users as instant-guide and has been one of the important factors in adopting the system organisation-wide.

Note:

We raised this issue with Microsoft support and it's team managed to reproduce the issue in its vanilla environment. But they informed that the feature is retired with the new look UI.

We are posting it in Microsoft Ideas as this site has been the most effective channel for influencing future product direction.