From what I see from the trailer, the speaker is possibly in the middle of the hinge, which is unusual because usually it's placed on the top. And it seems that headphone jack is possibly on the left of the stylus dock.
Mmkay, looks like I have saw several folks on the internet have played New 2DS XL hands-on thanks to some event, and I should take my word back about the speaker thingy in my previous post. One of the notable YouTubers out there said that the speaker was placed on the bottom instead (and apparently it's stereo instead of mono, if I'm looking at the design-wise. Pardon me if I'm wrong). He also noted that New 2DS XL is lighter than New 3DS XL, and the cartridge slot now has a cover to prevent accidentally removing it when in the middle of playing, which is a good thing.