Choice is key - look at women's athletics, some in sports bras and sports briefs, others in knee length body suits, and everything in between, each athlete choosing what they feel most comfortable in. I'm glad the German women - who it's worth noting are veterans in the sport and very well respected - are spearheading this movement to show that the option for a full length unitard exists. A 'shorty' unitard is permitted too, look up Qatari gymnast Jana Elkeky. But I don't think this means all gymnasts should wear a form of unitard if they prefer a leotard, many who have reached top level in the sport have grown used to and like the leotard. I think future generations will pick up the alternatives more as those who felt uncomfortable in a leotard won't leave the sport. I agree with PP who feel introduction of optional shorts would be good, a lot of elite gymnasts wear these in training so could see them being popular.
Men have leggings/tight trousers, and shorts because if they were in something close fitting to the body in the crotch region it would be frankly obscene, I have no desire to see the outline of the gymnasts genitals like male ballet dancers - on a stage from a distance is one thing, close up slow motion action replay we get with gymnastics would be quite another. Yes women have labia, but be real, the amount of outer genitals between the sexes is vastly different.
FWIW the women on Floor exercise don't have to smile and wink - they have to perform, show artistry, sell the routine, and be engaging. This can be a number of things, many find it easier to do an upbeat dance-y performance with a smile, but others, like Brooklyn Moors perform a tragedy. No smiling from her, in fact she spends the performance looking truly devastated and heartbroken, but she will see no artistry deductions as it fills the requirement just as much as someone grinning from ear to ear. In terms of different to mens, personally I would like to see mens floor including dance and music as it would make it more enjoyable.