The OP didn't say there wouldn't be defined male and female clothing. Most men would wear men's clothing, and most women would wear women's clothing. The OP said it would be OK (acceptable) to wear whatever you wanted (or nothing). Some would crossdress. But a man without that internal drive wouldn't wear a dress, makeup, and high heels. I would, but only occasionally, like it is now. I may feel more comfortable going out, though.
To suggest that we crossdress only because it's taboo means that there is no internal drive to crossdress, only the drive to "buck the system", and crossdressing is just the means.