It's kinda sad how CN was created as a "safe haven" for legacy cartoons, and now have one of the worst track records for making shows inaccesible of any TV channel - children's or otherwise. This isn't even a new thing with the HBO Max cuts, CN have failed to preserve their content as long as they've been making original content. Tons of missing specials (Ego Trip, Big Picture Show, e.t.c.), entire shows you can only get as 6-episodes-on-one-disc at best (Sheep, Robot Jones), universally revered classics only avaliable in full digitally (Chowder, Billy & Mandy), tax write offs, so on.
It's a case of "pick your poison" I guess - CN champions new ideas but always throws everything old out for a blank slate, while Nickelodeon fails to understand originality but can be pretty damn good at respecting and preserving their legacy. Disney TVA is probably the closest to a happy medium between originality and nostalgia in the industry, but even they tend to prioritise merchandising the Afternoon era stuff.