It depends on what part of the country or even state your in. States that have mild or no winter they will be fine, Up here in snow country during a harsh winter where you get a crust of ice on the snow it is a sure death for them without their mothers if their not adopted by other deer, I dont care what the DNR says.
Some places need thinning, some dont! Only the ones hunting that area has a general idea of what needs to be done if they have done their homework.