Not really fussing-worthy, no.
I think it shows how atomized and isolated War Thunder players are compared to other games though. I’m general terms we just want the other people in the game to be good AI and otherwise stay quiet while we grind.
I think it’s a misreading of their audience a little, is all. I think it’ll even turn off / drive away some players on the margins. But yeah you don’t put all that effort into service records customization if no one sees what was customized, so there’s a cash flow incentive for them to do this now, too.
A different way to do this people would likely have gotten more behind would have been a display of all your kills’ cards on your way out of the lobby, or a display of the card for “top player” for everybody on the way out, as other games do. No one would have minded that if it didn’t add to rematch time.
Just putting it on the kill cam, by contrast, only increases player annoyance with the game a teensy little bit each time they die, without any offsetting “good” feeling, because only the dead player sees the card. So yeah, not very smart, really, they could have done better with it.