I agree with you: convincing people that these systems do not have intelligence or agency is the second most important problem to solve.
The most important problem is to ensure people understand that these systems cannot be trusted to tell them the truth.
I'm OK with starting out with "these systems will lie to you", then following up with "but you do need to understand that they're not anthropomorphic etc" later on.
You might have better success convincing people if you stop bundling it together as "intelligence and agency", for starters. I agree with the agency part and strongly disagree with intelligence, for one. In general, "intelligence" is so vaguely and informally defined that it's simply not something that can be reasonably argued objectively either way.
(If what you really meant is humanlike intelligence, then I would agree with that claim, but it's a very different one.)
The most important problem is to ensure people understand that these systems cannot be trusted to tell them the truth.
I'm OK with starting out with "these systems will lie to you", then following up with "but you do need to understand that they're not anthropomorphic etc" later on.