Controversially, IMO banning types of play is often done with the adults in mind.
Play which makes our lives difficult or uncomfortable, such as battle play or schematic play such as transporting (often banned in EYFS settings as it makes the setting difficult to keep tidy). “My goodness me, Mrs Smith, somebody keeps emptying out the shells and filling the basket with other random things from the room! Who is moving things around? We don’t do THAT in nursery!” or “Charlie! What is that you have made from stickle bricks again? You know we don’t play with guns!”
Children are learning, all of the time, about the world in which we live through play. They explore ideas and skills over and over again until they can make sense of them. It is why as adults repetitive play/reading the same story over and over again is mind numbing, but perfectly enjoyable to them. It is also why, despite saying “we don’t play with guns!” little Charlie always finds a way to make one out of a stick or some bits of Lego.
Sadly, the world in which we live includes battles/wars etc. To make sense of it children will explore those themes through play, just as they do making cups of tea, or pouring jugs of water. As adults, who have already learned about the horrors of war, the permanence of death, the destruction to people’s lives, we find this kind of play abhorrent, but these children do not have our knowledge and their understanding yet.
Instead of blanket banning types of play, it is far better to observe play closely and interact with children to support/scaffold their learning and understanding in an age appropriate way. “What would happen if?” “How would they feel?” “What do you think it would be like?” Etc. Supported properly, a child will also learn our values, as well as benefitting from the choreography of social play.
We don’t allow our children to use fowl language etc, but how do they learn that certain words are unacceptable? Through support and picking up on social clues. We aren’t born with that knowledge, it has to be learned and how it gets taught will be different depending on the needs and experiences of the individual child.
By observing closely we can step in when play becomes too rough or when we think reenactment will be triggering for another child in our care. But all of that takes commitment, time and understanding from the professionals that work with our children and often one or more of those elements are are missing or stretched.
Sadly it is easier to look at the world, with the judgement of what we already know and just say “No!” rather than taking a step back and asking ourselves “what are the children trying learn/understand through this type of play? How can I help them achieve that in a more appropriate way?”