Originally Posted by Brugge

One card per 18 months applies to all of the personal Plat and Gold links.

The difference is the first (zombie) link requires you to wait from 12 to 26 months from the date you applied for ANY AA card, including the EXEC (YMMV). The reason the wiki describes it as not having "Explicit Churning Restrictions" is that the wait period was not written in the T/Cs, and varied from person to person.

The new links for the Plat and the Gold only require you to wait 18 months after applying for that specific card. This is the "Explicit Churning Restriction" that is spelled out in the T/Cs, and seems to not vary from one person to another.

So using the new links, you can apply for the Plat MC card if you haven't applied for a Plat MC in the past 18 months, even if you have gotten eleventy-seven EXECs, all of which are still open. Reports are this is true even if you just recently closed a Plat Visa. After that, you will have to wait 18 months before you can apply for a Plat MC thru the new link a second time.

The story is exactly the same for the new Gold app. Apply now if you haven't had one in the last 18 months. Then wait 18 months before you can apply for your next Gold AA card.