When tallying up the count of MCU characters who lost limbs, one can only come to one real conclusion: there’s an awful lot of them. This is, as it turns out, an intentional reference to another famous fictional character who lost an arm - Luke Skywalker. As Kevin Feige once explained to CinemaBlend:
I’m obsessed with Star Wars - and it didn’t start out as intentional, but it became intentional, including that beat that you referenced. It sort of happens in every Star Wars movie, but I was sort of looking at it, "Okay, is Phase Two our Empire Strikes Back?" Not really, but tonally, things are a little different. Somebody gets their arm cut off in every Phase Two movie. Every single one.
Feige is right about the lost limbs of Phase Two, but the amputations didn’t stop there. They’ve continued well into Phase Three and Phase Four, and will presumably carry on until neither the MCU nor Star Wars are popular - or, in other words, forever.