I recently just noticed that some A350s are missing their iconic set of 3 main SSAs (Side Slip Angle Probes) on their nose. I'm not sure if its an issue of newer variants or varied airline options, but I'm sure it has something to do with a less needed sense of redundancy. Any exact answers behind this?

Thanks!

Picture sources: Top:https://www.traveller.com.au/the-inside-story-of-the-a350-airbus-rival-to-the-boeing-787-dreamliner-12c17x Bottom: https://airwaysmag.com/airlines/british-airways-takes-off-a350-1000/