They simply want to prove that their expanded cryptocurrency ban is for their future projects related to their desired digital currency.
I believe their crypto ban is a ploy to create a stir. If they continue to uphold the Bitcoin ban, it won't affect Bitcoin itself, as we've already seen how Bitcoin has performed since the ban was implemented.
Every nation has its fiat currency and CBDC will be an alternative for traditional fiat currency only. Support or anti Bitcoin and cryptocurrencies depends on how government want citizens and commercial companies build up products, grow and gain wealth. Together they can build up individual, institutional and national wealth but only if government allows it to happen.
Chinese government have yet shown that they are too opened with such scenario, and they want to control everything, not because of Bitcoin or cryptocurrencies. Even before this blockchain and cryptocurrency era, CCP had history of centralized governance against their citizens.
Instead of worrying about Bitcoin, they'd be better off focusing on the BRICS.
China is a falling nation, and their effort to gain success with BRICS is falling down too. They can focus on BRICS or distract to something else but their national infrastructures won't support their growth in long term.
A nation with a dictator regime, with an individual dictator or a family dictator won't go too far to any good future. China exploited the friendly policies from the USA and Wester nations in several decades, together with their golden population era to thrive very rapidly but these things now changed.