"It is proposed that this exemption be adjusted so that foreign employment income will only be exempt from tax if it is subject to tax in the foreign country"
Your post reads to me that you will be taxed by SA unless you are taxed by your foreign country of employment. That's how it is for the US.
You are not double taxed if you are paying foreign taxes as they are "applied" to your US tax bill.
If they (foreign country) don't charge you income tax then the US demands what it thinks you owe (after foreign earned income exemption +/- $100k) regardless of where it's earned.