I definitely think shy clinton is far more common than shy trump - for a lot of the same reasons as shy Obama was always more than shy Romney. Demographics are destiny - and Trump sealed his own fate a long time ago - and a lot of voters marked "unlikely" are going to come out in droves to vote for Clinton, especially in the hispanic community. White men think their wives are going to vote for Trump, the reason why they believe there is a shy trump effect, but their wives are really going to vote for Clinton. And of course, there are people at the ballot box, facing their possible decision of voting for Trump, and ending up not going through with it because of WHO HE IS. These are right-leaning independents or even Republicans who are "for" trump but have been fighting with the idea of voting for him because, well, he's Trump.
Plus the fact that shy Clinton supporters have ALWAYS been "a thing." She and her supporters got hammered constantly from the left and right for over a year, so it's not surprising many would withdraw. Hell, sometimes I saw more Bernie stuff than Hillary stuff in towns she won by 50+ points.
