It was based on them saying on Facebook that they would be releasing two more this year. The obvious three markets would be lager, hazies and a British one (which in the US get used for more than just British styles), but the first two are probably bigger markets and there's the point they make about drying suppressing esters, so I think they go for a lager yeast and a hazy yeast. Look at what they have in their range, they've said WLP830 German Lager is their biggest-selling lager yeast (as it's their equivalent of 34/70, which is meant to be the world's most popular yeast) and WLP066 London Fog is their yeast for the hazy market.
So to be clear, they've said they're releasing two more this year, and it's my speculation that they will be WLP830 and WLP066.
I agree with most of what you wrote, I was hinting at it when I said "in practice, there won't be too much crossover, and presumably the deal works for them financially" but couldn't be bothered to spell it out. :)