Personally I’ve never liked the idea of NSFL. It just doesn’t feel like it has the eighth connotation, it’s wording feels like it’s meant to be a joke when it’s content is rarely funny. I think just using “Gore” or “Death” would be absolutely better.
If there’s prior work already using the technology, the patent would be invalidated. Parents are supposed to be used for innovations. Companies often patent things they shouldn’t, but if it gets challenged in court, it usually shakes out (although not always, especially since it can be expensive to challenge it).