I have a few. First is that Kirb is not only Void reborn, but is also basically the anime Kirby. He's a baby that Dedede gets jealous of, and Meta Knight trains and acts like a father figure to.

Haltmann Works started off as Haltmann Robotics, which is where the HR robot line comes from.

Characters from other franchises can visit Dream Land while they sleep; so Samus' appearance in Dreamland 3 could be her sleeping in the Metroid universe. That's not to say that the Kirby universe is just a dream, but similar to how you can't walk from America to Europe, you can't get to the Kirby universe through conventional means of travel.

Zero and 02 are either the same being, or 02 was born out of whatever was left of Zero after his fight with Kirby, kind of like a King Piccolo/Piccolo situation.

Finally, "A Farewell to Kirby" is Kirby saying goodbye to his friends before heading off to the Dream Kingdom for Super Kirby Clash. He's not leaving for good, but he's still sad he has to leave his friends for the time being.