[cylinder]

the entry ban will be for visa issuance at Consulates and entry into the US from abroad.

what you are talking about would require a rule-making process and/or statutory change. they are going to try that, but it will take longer and will be subject to judicial review.

AC21 lets you change employers without waiting for the petition to be approved. that's statutory. much harder to change as it would require Congress.

eventually, your visa label will expire. after that, if you need to travel overseas, you will need a new visa label and under this proposed exec order, if it's still active you will not be able to return. so you will have to avoid overseas travel entirely until the ban is lifted.