Are there standards or recommendations for the depiction of the 50 United States on a map with regard to the placement of Alaska or Hawaii?
Someone indicated there was a push (from who? how?) to show Alaska top/left of Washington State since so many people thought Alaska was near Hawaii… <grin>
Other than distortions caused by the usual problems, I don’t know of any standards for placing Alaska other than where it is connected. Moving Hawaii in is just convenience, to keep the map size and scale reasonable.
If you mean showing Alaska as a detached piece, I think it’s just a matter of fitting the two loose groups into whatever empty Pacific Ocean space is available. I don’t know that there are any formal rules or standards. Maybe there are in Alaska. 
I don’t think I’ve ever seen a map where Alaska wasn’t off of the coast of SoCal, and Hawaii tucked in the space in between. Which makes sense to me.
Who would enforce the standards if they existed? And how could they be enforced?
And why would we NEED a standard? Different renditions of the US might have differing numbers of insets to be displayed (there might be a lengthy legend, for instance). And you may wish to show the states in isolation, or with the land areas for parts of Mexico and Canada included.
Lower left corner is often used because the shape of the mainland US, with Texas and Florida sticking down, leaves a lot of empty space there. Particularly if you aren’t showing Mexico, or don’t mind obscuring it. The Gulf of Mexico is also convenient. But there’s no need to enforce a location.
You can see Jerry Brown’s house from Wasilla.
As a professional mapmaker, I’d know if there were a “standard.” Just this week I was pondering putting an Alaska inset off the east coast of Florida, where I have the most empty room given the conic projection I’m using. But that seemed too odd.
Back in the 1970s, USGS published some maps of the US with both Alaska and Hawai’i in their proper locations to make a point. But that means a map that covers a third of the globe, unwieldy in most contexts.
If Puerto Rico becomes a state we’re likely to have the same issue with it as well. It’s not terribly further east than Maine, but it’s quite south of Miami and there isn’t a lot of America out there in the Caribbean and now Cuba, Hispaniola, Jamaica and a few other lands are stuck as grayed out areas on the map. As of now PR is treated as not quite exactly foreign but sufficiently non-domestic that it doesn’t need to go on ordinary US maps.
I hate map insets. If you can’t show something in the proper place and at the same scale as the rest of the map… it belongs on a different map.
I rather like a method I’ve seen, where a tiny map of North American is includes with boxes to show where each inset comes from. Then again, if the obvious (usually rather thick)sectioning of the map and new scale doesn’t clue you in to the fact that Alaska is not off the southern coast of California, maybe that wouldn’t help you either.
BTW, just because something is a standard doesn’t mean that there’s anyone to enforce the standard. It just means that there’s a generally accepted way to do things. The enforcement can just be by others doing the same thing. The creation of someone to enforce standards is usually a later addition to the process.