That's a bold statement. Have you got some good source? I'm having a problem imagining a statistically relevant number of people saying "I'm interested in pursuing one of the skills marked by the government as experiencing national shortage, (for years!) but I won't because immigrants will take those positions instead"
- Relative size of CS departments (enrolments) and how standalone they are as a faculty now vs 10-15 years ago
- Observations of how many parents who work in IT recommend to their kids to pursue alternative fields of study
Statistically I am not sure how this fits in with other non-IT fields.
Personally I would love to see the points above greatly improved upon as computers are here to stay, so having self-sufficiency and cross-generational (family) expertise would be very complementary and competitive.