Sorry, wrong link. There isn't an English product page yet. Here is the Chinese version:

https://consumer.huawei.com/cn/phones/mate-xt-ultimate-desig...

I've just watched a product video and a bizarre 'brand' video of a guy turning around for several minutes and I'm no clearer on where the 'tri-fold' is on this phone.

I think you're right, it's a regular handset?