As you could see on Reddit and other resources, such Mercedes variants were never manufactured under Maybach branding.

Number of such converted vans are increasing everywhere - I even took one on Uber in Amsterdam. Investors are mostly buying Mercedes cargo vans, not even passenger vans. Because cargo vans are cheaper. Then they are converting them into "Maybach" vans.

I agree they look fancy and the interior is posh. However in those cargo vans they have leaf springs in the rear and leaf spring is so bad for passenger comfort. Maybe in more developed countries they are only able convert passenger vans but in Turkiye there're high chances that you'd end up on a van converted from cargo.