For folks in the networking space, differentiating between L4 and L7 proxies is pretty important. And while you could call it an HTTP proxy in many circumstances, some proxies support other protocols e.g a mysql proxy.
In my last role I started trying to enforce this by refusing to use the terms "Layer 7" and "Layer 4" (I worked on application and transport layer infrastructure at a big tech) but it never caught on and after having to give "the talk" about what happened to OSI Layers a few times I resigned myself to the fate that it was never happening. I will continue to use those terms though.
I think it's only misleading in that the only L7 protocol it supports is HTTP. It's not a huge deal, but when I work with other proxies if I see L7, I assume multiple application protocols.
