Maybe he suppressed it? Or this is just showing that Trunks is absolutely terrible at Ki sensing, leading into why him and Goten couldn't sense Piccolo laterTrunks didn't recognize Gohan's ki?
I'd love it if the reason him and Goten are so bad at sensing ki is that their "sensors" were blown out by being 5 and 6 when massive energies like Buu and SS3 Goku existed. They never got time to "grow that muscle," so to speakMaybe he suppressed it? Or this is just showing that Trunks is absolutely terrible at Ki sensing, leading into why him and Goten couldn't sense Piccolo later
I would love for both Cooler and Janamba to be introduced later in the canon story. Cooler being introduced later on in the eventual Black Frieza arc would make sense too considering Frieza would be the kind of person to never mention their brother once. He wouldn't care about him one bit lol. As for Janamba, he's kind of a great villain for even people like Krillin or Yamcha to go against, considering his weakness is cursing. So even with power levels where they're at currently, they could still have some relevance in a theoretical arc.Wow, they actually made Olibu (similar to He-Man/Conan the Barbarian) canon to Dragonball world.
Will Cooler, Pikkon, some noteworthy characters be made canon later down the road? Found out on the next episode of Dra--Oops.