I don't see why this pool should logically get smaller. In the other hand though, the USA avoids the way, other countries are handling job training , like the devil water.

No, skilled labor gets more important from day to day. But it costs more. So let's hire people that will settle for less, and kick them out if they reach there limit.

In most countries, you have a multi year on the job training + school before you consideres a skilled worker in this job. I for example carry the title of a "Journeyman of Electronics and Communication". I am not working in this field anymore, but usually, most people stay with that they learned.

Long ramble short: no the pool of skilled jobs is shrinking, capitalism is expanding