YouTube teardown specialists iFixit has posted its dissembly video for the Huawei Mate Xs. This device has a flexible display found on the outer face of its phablet form-factor. It has also now been found to contain various serious obstacles to getting at its internal components.
https://www.notebookcheck.net/iFixit-s-Huawei-Mate-Xs-teardown-does-little-for-the-foldable-category-s-reputation-for-durability.461035.0.html
Dust ingression is not the main threat for foldable devices, as long as you don't usually use them in a desert. As for liquid, I'm not aware of any liquid protection for this model either.