The term Cottage Garden is definitely not anything new. I am finding it used in books going back at least into the 1700s. I like to think of it as imitating nature...
"Those who look at sea or sky or wood see beauty that no art can
show ; but among the things made by man nothing is prettier than
an English cottage garden, and they often teach lessons that 'great '
gardeners should learn"
~William Robinson, 1883