If there's less immigration, then the working age population growth has to be less, so the number of new jobs you need to break even is less. I mean, it's not like they shouldn't spell this out, but it would be weird if this weren't true.

One thing they _didn't_ mention here, that could also impact this. The birth rate dropped dramatically in 2008, not unusually for a time of economic contraction. Unusually, it stayed low ever since. 2008+18=2026, so starting next year we should expect to see fewer than normal people aging into the workforce, while 1960(the end of the baby boom in the US)+65=2025. So, while the number of people coming of age will be lower, the number of people aging out will also be lower than it has been for the last 20 years. I'm not sure how this balances out, and there is also an impact from changes in how many people go to college, but we could be seeing a demographically-driven labor shortage starting soon.