Yes, Microsoft removed the footer support and the controls/contents cannot be added there anymore.
Form footers in model-driven apps won't be supported with the 2021 release wave 2
With the upcoming 2021 release wave 2 (public preview in August 2021 and GA in October 2021), form footers won't be supported in a model-driven app form.
The footer doesn't meet the Microsoft Web Content Accessibility Guidelines (WCAG) 2.0 compliance for accessibility.
Main forms will no longer include the footer when a record is opened. Any out of box or custom controls that have been added to the form footer will no longer be available and you'll need to remove the fields if they're no longer necessary or move the fields to the header and use the high-density header with flyout or add them onto the main form. The recommended approach is to move fields that users need to access regardless of the form tab a user is on to the header and set it to use the high-density header with flyout. If there's only one tab, the recommendation is to move them into a new section on the form.
The out of box fields currently on the footer is removed and included on the form as part of the 2021 release wave 2 updates. So, you don't lose status, unsaved changes, or the option to open a form in a new window. The Save option is already available in the command bar and is always visible to the user.