That seems to be the case as the two devices reportedly use MediaTek Helio G8x chipsets (MT6969T and MT6769V/CT). The 10X 4G has a G85, the Redmi 9 has a G80, so we’re in the right ballpark. Depending on the specifics, we may be looking at the Redmi 9 and a Redmi 9A (a model that doesn’t officially exist yet).
The Redmi 9 still hasn’t made an appearance on Xiaomi’s official website in China, even after its European debut. Of course, the Redmi 10X duo has been selling well, so maybe the company wants to leave it some breathing room before unveiling two more affordable models.