This should purely be a buff. A reliable moderately powerful projectile that you can throw out at will is far more useful than a unpredictable, slow, and most of the time very weak projectile. It'll be a great combo ender, and could be a great anti-projectile move; if it clangs with projectiles as normal, it's going to be really amazing, as it should still deal around 15% damage, allowing it to outpriotised all the weak uncharged projectiles and go right through them. If it does this, it will really help Dedede not be so vulnerable to projectile camping.
Sure the Waddles provided some utility, but it was all minor and doesn't provide the outright usefulness the Gordo Toss can, and decent players will avoid getting trapped in Waddle Doo beams most of the time.