This would be correct. They would not qualify unless they received a 1095-A. Per the instructions here: https://www.irs.gov/pub/irs-pdf/i8962.pdf
You may take PTC (and APTC may be paid) only for health
insurance coverage in a qualified health plan (defined later)
purchased through a Health Insurance Marketplace
(Marketplace, also known as an Exchange). As a result, you
should complete Form 8962 only for health insurance coverage
in a qualified health plan purchased through a Marketplace. This
includes a qualified health plan purchased on HealthCare.gov or
through a State Marketplace.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Accept as solution"
