The problem with China isn't Trump or the trade war. That has nothing to do with it. Toys aren't impacted by the tariffs, and in any case the tariffs wouldn't impact sales in China.
The issue is simple: Mattel massively over-shipped in China for several quarters in order to post consistent double-digit growth, but POS was totally mis-aligned with this shipping. As a result, Mattel and its retail customers are working through a huge backlog of inventory... and this means no more shipping until it's cleared.
This post was buried in one of the threads on this board. @VPaiMGj-3wsy certainly got it right. Very true.