The first mistake made here is, Disney plots are their own genre, and have been for many years. This plot does break some Disney tropes, but if you look closely, all the beats are there still. As a father and uncle, I appreciate this movie that is less male-centric.
There is a lot of subtly in certain places-- the song between Anna and Hans, "Love is an Open Door" -- while the trap set is abhorrent-- if you understand the lyrics, these characters are not talking about "love", they are talking about second order effects of running from their (psychological) problems. In the song, nobody says the only thing that someone should say, "I love you because you are you." Rather, the song is purposefully shallow, "This is how you make me feel, about me."
Moving on...
The Trolls are equivalent to the "prophecy" trope we see in so much bad entertainment nowadays. They essentially lay out the entire movie for you. This is frighteningly common but one could argue in a movie for children it might be good to let them know whats going on. The Trolls just tell us the prophecy in an amusing manner, instead of being some boring scroll that was found or exposition that was told to us. They get a silly musical number, and honestly why are you watching a Disney movie if you didn't want a silly musical number by cute anthropomorphic, marketable things?
The Trolls advice is indeed baffling... but the motivation to hide Elsa's powers are very well established-- magic is feared and punishable by death, and its even playful use directly harmed Anna. You could probably overlay real world problem here as a metaphor... The fact that the article misses this obvious point makes me wonder about the authenticity of the authors intent at all.
The Trolls are a plot device in a movie that, was overall pretty-ok. They're not evil, they're just an escalator that moves the plot along.
I like that the movie deviated slightly from Disney-standard plots. I don't want my kiddo to think a man needs to save her... we have a rule around here, "She can have as many Barbies as chemistry sets."
Overall, it was a decent film. Fantastic movie, fantastic animation, and an "ok" plot. :-)
Frozen 2 was more... wonderful and silly. I liked the film, the set piece at the denouement was wonderful, but we have to explore that Anna is obviously the spirit of fire, which wasn't broached.