Plenty of such stuff in W3 - a ghost woman is on the bridge to Blacksburg - again, she is there only at night, so a lot of players missed her - she gives you a quest to bring her wedding ring to her dead husband, yet if you dont have Keira's lamp, you wont be able to see what is really happening.. etc lots of things like this are placed all around W3 world...
Anyway, story wise, Witcher 3 story is most personal.. In W1, ok, they stole mutagens from you and killed one young witcher, yet it is nothing that would destroy Geralt completely... same in W2, ok, they blame you for Foltest death, but again, Geralt can live with it, and eventually, even forgive his killer for what hes done (at least i always did forgive Letho), yet, in Witcher 3, its all about saving one person that is the most dear to Geralt - Ciri.. so personally i don't understand people criticize lack of explaining behind The Wild Hunt motives... no father would try to understand motives of a kidnapper who wants to kidnap and kill his daughter.. so why they want this from Geralt?? Plus, entire motivation and whats going on, is still explained indirectly to players that payed attention - Tir Na Lia is being slowly destroyed by the White Frost, and Eredin wants to save his race by opening the large portal and perform full blown invasion into Witcher's world (and kill all humans once he is at it) for what he needs Ciri (or at least her body)... Avallach at the other side, wants Ciri's help to stop the White Frost instead... so yeah, i think story wise, W3 dominates both previous games.