thematic elements

It's a bullshit excuse for a movie to be rated PG for no reason whatsoever. It's no different than watching a G-rated movie from the 70s and 80s.

Modern Disney and Pixar movies are given this rating and description because studios think they won't appeal to a modern broader audience.

Why the hell is Frozen rated PG for thematic elements?

That's like rating every Disney movie from the 50s and 60s PG. PG-rated movies from the 70s and 80s feel more extreme compared to today.