Wait a few years. Outsourcing is largely a means to undercut technical workers as they get into their thirties and forties. I hope it never happens to your sons, but they always need to keep an eye out for changes in the global job market and adjust their approaches accordingly. I made a shift from a technical position to a business-technical hybrid, and shifted from financial marketing to pharma marketing, and both have paid off, not so much with a significant increase in income, but from having a defendable job. It is also good to have a highly diverse technical background - I've done just about every job in IT.
You are absolutely right, and you planned your career wisely. I’m confident my kids will do the same.