With the exception of range and missile flexibility the recent HQ-9 variants are superior to the S-400.
I think it's fairly unlikely that the HQ-9B mod 2023 has the same capability as mod 2006. China just stopped updating their designation at some point. There's not exactly any tech barrier towards making them longer ranged, and China's export offerings all skirt the maximum allowed range for export missiles, so it's hard to believe that their domestic use missiles won't be even longer ranged.
Before the 2022 war, Ukraine had succesfully modernized some of their S300 and Buk, but did not reveal it until the war started. Similarly, China today is a country under threat of invasion, so it is better to keep an extended range HQ-9 under the same designation and public specs, and then if/when China is attacked, the enemy will be surprised by HQ-9 when they thought they were out of range.
