Redwood will become a requirement/mandatory in the 25A release ?

Client Villages has created a different landing page in Fusion Cloud Vertically (image below) using by Sandbox.  They are anticipating that Redwood will become a requirement/mandatory in the 25A release, that will be decommissioning the below UI page to horizontally ? is that correct ? How that Redwood changes 25A is going to effect on this Landing page/Sandbox setup(Vertical).