AGI is not a new term. It's been in use since the 90s and the concept has been around for much longer.
I agree that we should use more specific terms whenever possible. I call LLMs "LLMs" or "language models". Not that it's inaccurate to call them AI, but it's not useful either. AI is an extraordinarily broad term. Pac-Man had AI. And there's a large portion of the population who thinks it means something much, much more lofty and specific than it ever really has. At this point, the term should probably be abandoned. Any attempt to reclaim it is bound to fail.
I see this as yet another example of a technical term being bastardized by mainstream press who do not understand the field. It happens all the time with tech. I remember when "virus" actually meant something; the industry eventually abandoned the term because it was bastardized to the point of uselessness; now we just say "malware" and if we need to refer to viruses specifically...well we just don't for the most part.
This is a linguistic problem more than a technical problem.