Hi JSG3,
To be clear, you are not required to upgrade templates to use dnd_areas. Flexible columns will continue to work and there’s no plan to sunset them.
It does not make sense to upgrade 200+ pages to use dnd_area to make them look the same as they are now. Changing to dnd_areas on it’s own will not suddenly result in an increase in leads or profits. As you said they were built with flexible columns, they already have a great degree of power and flexibility to them as a result.
Making dnd_area versions of the existing templates is most useful for new pages, or for when you want to revamp an existing one of those pages. If your existing pages are serving their business purpose as is, and you wouldn’t normally be doing a redesign of the page’s template, then it doesn’t make much sense to convert.
This feature is additive, and a different concept than flexible columns, it is not a requirement. Flexible columns and dnd_areas can be used in tandem in the same templates. We do advise having at least 1 template that uses dnd_areas in themes, to give content creators flexibility. That however is just a recommendation, you can still build with flexible columns.
Hope that helps.