Presumably these are new subdomains, if a caching DNS resolvers never saw the domain yet, it would simply query the authoritative server.

There's a small nuance here that DNS spec also caches negative (NXDOMAIN) results, but the TTL of those is controllable by the SOA record on the domain that contains it.

exe.xyz has a fairly short 10 second negative TTL, so even if you tried to resolve it before it was set up in the authoritative DNS, it wouldn't stay negative-cached very long (though some DNS caches put a lower bound on the TTL and cache it for longer)

> dig +short soa exe.xyz

ns1.exe.dev. hostmaster.exe.dev. 1854440 86400 7200 1209600 10