You are talking about the partnered third party exchange that Trezor has got. If you are using them then be prepared anytime for them when they start asking you some compliance for your ID. As for Uniswap, it's a good one for the altcoins that he's about to sell but if it's about Bitcoin. You can't sell it there and don't be confused about the BTCs that are listed there because they're wrapped and it's under some networks not with actual BTC's chain.