newer dresses tend to be chiffon with tulle lace. those dont match the weight of thick old school blouses, socks, cotton lace. if you can find a newer dress styled the way older ones are then go right ahead but i personally find the mismatching of new and old to be jarring. because old school was the birth of the fashion it does tend to verge on "this isnt like the new stuff, so is it really lolita?" the answer is yes it is lolita, but if you take away key aspects of old school lolita it would no longer be passable.
"everything suitable for lolita" from three different eras really wouldnt make sense. want to mix a newschool tulle lace covered bonnet with ott sweet era print with old school platforms from meta? you do you man but its going to look disjointed