The issuance of CBDC is a huge publicity for digital currency. When CBDC is issued, many people will learn about the existence of digital currency, and thus will also know Bitcoin, a digital encrypted currency. There may be ordinary people who understand digital currency because of CBDC, but they may like to invest in Bitcoin.
It may only play a superficial propaganda role for cryptocurrencies, but the central bank and their digital currencies will never do anything for Bitcoin. They will think that cryptocurrency will threaten their projects and will be detrimental to the development of CBDC itself.
I feel like everyone in the world already knows about bitcoin, not like anyone is left in the world who didn't hear that will end up hearing about it with CBDC. I am not saying everyone is involved in crypto, they are not, mainly the older people do not join crypto because they are already either doing fine, or do not have the time for it. However even if you are a 70+ year old person who has no interest to crypto at all, you saw the news about bitcoin skyrocketing once a year on television.
It is why it is not a shock that they will see another CBDC news but that's about it, nothing will change for them, it is just something else regarding crypto that they will ignore. I think this is the max we can reach in the crypto world at this point, we will have more and more people in the future but that will be from younger people earning money, not older people earning money.