There has long been an effort to encrypt DNS queries between the client and the recursive server to increase privacy. Firefox already supports DNS-over-HTTPS. But is Tor Browser, executed from Tails, compatible with DoT and/or DoH?
Tor always uses SOCKS5 and requests DNS over Tor. This is a requirement if you want to access onion services. This is the same on Tails as it is with Tor Browser for regular Linux, Windows, or Mac. If you use Tor with any other application outside of Tails, you have to manually make sure that application allows that kind of proxy.