Hey Shawtay!
Yes during the tournaments the raids can appears, for example, the first day the Tournament TRIUMPH was launched, in the server Endebra appeared the Zzaion raid where the Zulazza the Corruptor respawn, of course, noone went because noone had level and power enough to kill it. Sadly I dont have any screenshot to prove it.
But honestly, in my opinion, those bosses aren't worth defeating during tournaments, based on the point that most of those raid bosses are "worth it", for the rare items you can get from them, but during the tournament, people aren't looking for rare items, so it's better to focus on bestiary and level up.