After the AA loose seat fiasco, the FAA has issued a Special Airworthiness Information Bulletin for specific models of Weber seats:
Note that some of the listed aircraft types are no longer in service. Affected seat models include the 4001, 4004, 5150, 5200, 6002, 6200, 7001, 7501, 7502, 8000 and 8001 models.
Interestingly though, even though the 5150 is one of the affected models, it appears that DL's 764ERs and ex-Song 752s (which have the 5150 in Y) are not affected. I wonder why not. It appears that in the current DL fleet, the Weber 4004 seats on the non-AVOD PMDL 752s and 763ERs are affected. The table didn't include the 772ERs either, which formerly had Weber 5150 seats as well. However, the table did include the 738s, which also formerly had Weber 5150 seats.