Film and Video presets have an unnecessary Artboard 2
Every new document created has 2 artboards (At least when creating from the 1920x1080 HD video template) Every time I go to export a jpg or png via save for web, it slows to a crawl because of a huge unnecessary artboard. I only want to export the size artboard I created, the HD size. But I have to wait for it to catch up and then cancel, delete the useless artboard, then go back to exporting. The whole process takes several minutes and is infuriating.

This artboard has a purpose.
As mentioned here in comments and in several discussions (here or here), this artboard is needed when importing the file as a composition into After Effects.
Quoting Ton Frederiks (thanks):
With a single artboard, After Effects clips the content outside the artboard even when Retain Layer Sizes is selected.
With the second large artboard, AE will show the contents of layers when Retain Layer Sizes is selected.
Another way to solve it is to create a single large artboard that has the size of all the artwork.
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Ton commented
The large artboard is meant to help animation in After Effects and prevents clipping at the main artboard.
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eduardo asta commented
I have being experienced the same issue.....