This tragedy directly reflects a change in the way Japanese media standards work. Media in Japan doesn't often use boys for sexual purposes; that territory is exclusive for girls. The result is that in a culture that was starting to see female nudity as "for adults only", Doraemon and numerous older series became obsolete fast. It's entirely possible that those older episodes can't even air on television anymore.
Not helped is the American market. Despite the existence of these toned-down scenes, they were still censored for the US broadcast of the show. Most notably, Shizuka (called Sue in the dub like some 4Kids production) was reduced to having to take a bath in a swimsuit. Considering the idea of a bath is to clean your body, one wonders exactly what she's supposed to be cleaning.
On its own, it's easy to blame globalization and American dominance changing these standards... except just one year after the tragedy, two vile, evil anime were produced that changed the way loli nudity was used in Japanese media. They were Kodomo No Jikan and Moetan, and both of them used extremely sexual fanservice with underage girls. Kojika's anime would even censor the episodes on TV, only to release lurid uncensored versions on DVD. Moetan was similar, but got away with a massive detail of sexual content in its broadcast version, all involving underage girls or girls meant to look underage.
That these two series were able to become such smash hits, so notable and high-profile, while a newly-censored Doraemon couldn't even scratch the surface... it meant bad tidings for the industry...