Another thing to note is the winglets on the originally purchased 175’s were the enhanced winglets which over time were shown to degrade (show cracking and loss of structural integrity, however was never a safety of flight issue being winglets only served as a way to help fuel economy and if detached they didn’t effect safety of flight) At every heavy maintenance cycle they were to be replaced, or if they showed degradation prior to a heavy maintenance cycle they’d be replaced right then. It’s likely these weren’t replaced yet.