I believe a radical idea is an idea that is completely new and completely turns the status quo on its head. This idea, however, doesn't seem all that radical. The idea is definitely different, but not worth writing home about. I think it definitely is a very interesting idea and I would like to know more.
No, pretending to be in 1950 while the film is shooting is not only unoriginal but implausible. First of all, period films are nothing new. Secondly, many actors subscribe to "method" acting, a technique developed in the 20th century where actors try to become their character in everything from their personality to their clothing. Not only is this an old idea, it can be harmful to actors' mental health; for instance, it led the death of Heath Ledger while he was playing The Joker. As for directors and staff pretending to be in 1950 while shooting, they would presumably also have to pretend not to understand modern film equipment, workplace safety regulations or civil rights protecting female and non-white workers on set. Nor could they ever leave the set during the long shooting process, since to do so would force them to deal with the modern world and shatter the 1950 illusion. This is not a radical idea; it's simply impossible.
Very few ideas are radical, this one doesn't sound a particularly radical idea. With time rolling by and so many people involved in film it makes it difficult for those involved in the industry to come up with any good ideas, let alone ones which are truly radical and could have an impact a wide audience.
Whenever a film is based on a story set in the past, everyone involved has to recreate that era. The costumes, hairstyles, film sets and the type of language used need to be authentic. Even the food and drink has to be appropriate for the time. Viewers are quick to spot anything that does not fit into that time, especially if it is technology that had not even been invented.