site number one as a guide to the crypto market and also a list of crypto, the information is always accurate. but there are notes, altcoin or new tokens are sometimes indeed listed on coinmarketcap, but most are already there.
The CMC is only added a new coin which was already meet the requirements but it looks like you can get more coins at coingecko because it has a easy requirements compared with the CMC. For me to get the list of a new coin and i still prefer coingecko and CMC will be the second destination for a new coin after it has already completed the requirements.