They are definitely lure sets, however again the difference is opportunity cost. The opportunity cost of running a set like solar beam heatran or colbur berry slowbro in gen 8 for gastrdon and weavile, respectively, was the loss of a moveslot for solar beam and body press, that could replace an important move like heatran’s toxic, for one that was worse in every matchup other than the one you’re luring, so if you don’t run into it good luck with your neutered mon, and an item slot, where you give up tran’s leftovers and slowbro’s boots/rocky helmet.as mentioned lure sets are something that have an opportunity cost and imo changing your tera type from tera water to tera fighting on gholdengo to kill kingambit easier is not a lure set, its just playing guessinggame imo
With tera the opportunity cost is... not having a different tera type. These lures can also work outside of their specific mons also, suck as gholdengo teraing into fairy to avoid an ohko from dragapult’s shadow ball when the actual reason to run it is for gambit’s sucker punch. There’s no reason not to run a set that will beat a mon’s checks (unless it’s tera blast actually, that move is dead weight until tera kicks in) other than you could run one to boost your stab or beat another set of checks. It’s absurd that mons can escape losing 1v1 scenarios and turn what should be an easy endgame for the opponent into a 50/50.