AA offer members an opportunity to obtain lifetime Platinum (OW Sapphire) and lifetime Gold (OW Ruby). However they offer no opportunity for lifetime OW Emerald equivalent status.

Interestingly BA offer lifetime Gold (OWE) but no option to obtain OWS or OWR equivalent.

Since BA lounge access is based on OW status, I can see how lounge crowding may become an issue with a large number of lifetime Silver (OWS).