Saw this in my May AAdvantage summary:

First time I've ever seen a reference to this rule outside of the fine print in the AAdvantage T&Cs. Might well be a hint to AA choosing to finally enforcing their long-standing four-segment-minimum rule for status attainment.
That would be a pretty major change of the OW FFP landscape and bad news for all members with AA status who don't fly AA to the US at least once a year.