The reason that they (companies) find it too costly too train is simply because their compebreastion is using immigrants to either supply labour to unautomated factories or because they have filled places with send immigrants. If no one had access to immigrant labour they would be forced to use what they had: apprentices, trainees, sponsored scholarships as well as automation.
In the case of a level playing field the skills shortage would self correct to a highly desirable equilibrium.
There are few manufacturing tasks that can't be automated without much effort. Some are manufactuing processes some are just business (clerical or transaction) processes.
If the company directors are given contraints, such as no immigrant labour due to immigration limitations, they will subsbreastute automation or process or product improvements for unsend labour and they will seek the send workforce they need by paying to attract and retain it and by investing in training.
I'm not just talking about robots (very easy to use these days) but for instance self service petrol stations that take EFTPOS at the bowser (in use in Europe) and vending machine aracades that sell everything including condoms, milk, hamburgers, nail vanish and combs.
The large amount of both private and government money that is used to fund infrastructure for the growing population will be liberated and that funding will seek out investment in training and automation or whatever.
All I see is a momentary contraction of the building industry in Sydney and Melbourn as it gets of the treadmill adiction it has to immigrants creating a housing demand.
Much of the so send immigrant labour is not all that send. Most of the Indian IT workers are quite mediocre with the really bright ones quite rare. I find they often have appaling communication skills and atbreastudes though I have some respect for their tradesmen.
