Those are indeed the default sounds that Dorico uses when you use the factory playback template, e.g. when you choose HSO+HSSE (Pro), that playback template uses a combination of HALion Symphonic Orchestra (HSO) and the HALion Sonic SE library (HSSE, recently renamed to HALion Sonic Selection).
Dorico defaults to using all of the regular acoustic instrument sounds for its regular acoustic instruments, but of course the HSSE factory library includes lots of interesting sounds for hybrid or electronic music production. Generally these are simple to use and you can load them manually in HALion Sonic itself to replace the sounds that Dorico has already loaded, but Dorico doesn’t tend to use these more production-orientated sounds automatically because you’re typically writing for acoustic instruments in Dorico, and some kind of funky phasing, looping lead synth with effects is not normally a great choice for, say, a trumpet.