The real unicorn factor is the M30 aka metric freewheel threads. In terms of a complete wheel there probably isn't anything that can replace it directly because of that, even if all the other unusually-fancy-kid-bike boxes were checked (16 spoke, 16", non-coaster).
The point of the M30 FW is to run a 14t, which standard freewheel threads can't do. All 14t singlespeed freewheels need the M30 threads.
Left-hand metric/M30 freewheel threads were used on some BMX bikes to run left-drive, which is a different animal completely than what you need but is something you might run into if you go digging for a metric freewheel hub, so you have to be careful about that. A lot of them are also 14mm; metric 3/8 hubs are a fairly unusual combination, again even without the 16h etc.
Metric FW hubs are also often referred to within BMX as "flip flop hubs," a different use of the term than on adult bikes. BMX flip flop hubs have regular FW threads on one side and M30 on the other. They come in all permutations of left and right drive so you need to be careful to get the right thing.
If you had to build a wheel that does the job, most BMX race cassette hubs could do the same job, since they can take 14t cogs (other than one piece driver types). Those are mostly all 36h only, but coming up with a 36h light, narrow 16" 305 rim is probably possible - you would likely do that by buying a BMX-y kid wheel that has one and taking the rim from it. If you could find just a right hand drive metric FW hub in 3/8, you could do that too, but tracking one down might be tricky. The 110 isn't the problem; that is the standard for all these bike types.
The Woom 3 rear wheel is similar but with a conventional freewheel, not metric. It is a 16h 305 though. You could buy that and rob the rim to rebuild your hub. You should plan on needing new spokes and they are going to be an odd length, so have it built by someone who can just cut the spokes.
Depending on whether the old wheel is simply taco'd versus having point impact damage (dents, flat spots etc), the first thing I would attempt here is just unbending it the old-fashioned way to the point where it's truable, ie smacking it.
Basically any single wall basic aluminum rim in the approximate width class will do the job here, ie a Weinmann 509 or Alex X101. The problem is drilling if you were to try to re-use your hub, since 16h 16" is something Islabikes made up. It would more or less work to build that hub into a 32h rim, but that's also not a common 16" 305 drilling. The main expedient way to obtain
There is no fast solution here, and Islabikes is right to be suspicious that the rim really is the only casualty here, so there's a lot to recommend just buying a new bike.
