I feel like the fanbase should really be pushing harder for more character interaction. It's such a basic aspect of most fighting games that is completely absent in Smash, save for the very small amount of characters with one or two specific custom victory quotes (and even then, there's Simon who just truncates "I vanquish the darkness" to just "the darkness..." when facing certain characters).
Like, even NASB had this to an extent in arcade mode, even with the absolutely baffling executive mandate that the game couldn't write new dialogue and had to use existing quotes from the show. Playstation All-Stars had full on memorable, albeit silly, rivalry cutscenes for the arcade mode. And Multiversus had newly recorded custom crossover dialogue for huge portions of the cast, despite being a free to play game.
There's absolutely no reason that Smash, with its behemoth of a budget, shouldn't have this. Obviously if certain third parties wanted to opt out that would be one thing, but there's no real excuse for the first party cast at least. Smash advertises itself as the ultimate crossover, but refuses to budge on this extremely basic aspect of such a crossover...the opening cutscene for World of Light is like the lone example outside of one off codec instances like the Slippy codec in Brawl, the Chrom guidance in 4, and the Alucard guidance in Ultimate.
People love to just write it off with the oft-repeated "Shulk monologues only for the response to be pika pika," but the vast majority of Smash's cast is capable of speech through either spoken dialogue or text boxes. It's a non issue. The only issue is Nintendo cheaping out.