Uniswap is completely decentralized. Uniswap Labs cannot prevent any one from listing any token on the Uniswap smart contract, or prevent any one from setting up their own frontend to access it.
Oh yes definitely. But there are numerous other front-ends available. People can even run their own front-end locally. People generally don't because so far there has been little need.
The option to use other front-ends, and the inability of any central authority to shut down the Uniswap smart contract, is what makes it censorship resistant.