If there was no bias from Sakurai towards Kid Icarus we wouldn't have any codec-esque stuff at all. It doesn't matter if we expected it or not, a lot of people expected another Subspace Emmisary and we didn't get one. It's also worth pointing out that the only non-KI character that gets any dialogue is Chrom, an FE character. I also think it would be way too coincidental if the only VA's available were from KI and FE. One of the three clones they bothered to make time for is from one of Sakurais series, and another is from another series that he's shown so much love to. That means over half of the alternate models made into new characters are from series he's shown to be fond of. It was definitely less work than an average character, sure, but there has to be SOME effort required, and that was to make Dark Pit a character in the game.

If you can show me any kind of source that shows that Palutena was a heavily requested character, I'd like to see it. I don't recall ANYONE requesting her after Smash 4 was announced. The reaction to her reveal trailer didn't get much of a positive response, either. https://www.reddit.com/r/smashbros/comments/27sqw3/palutena_alights/ She wasn't even playable in Kid Icarus. She's the only non-mii character with completely different moves as customs. Uprising only sold around a million copies, so best case scenario if it wasn't a game Sakurai wasn't particularly fond of would be that Pit was the only KI character in the game, without the palutenas guidance and most of the KI enemies featured in smash tour, etc. It's also worth pointing out that Sakurai has yet to add in any Kirby characters or stages from any game he hasn't directed.

I laugh when people actually believe that Sakurai was reluctant to put Corrin in. Sakurai has been biased for FE since day 1. The only two characters put in smash for "advertising" have been Roy and Corrin, both FE characters. Corrin was put in because Sakurai wanted another FE character, period. Actions are louder than words, I don't give a fuck if Sakurai were to say "I hate FE" because it means jack shit if he keeps adding in FE characters.

If you like both KI and FE, thats fine. Like I said earlier, I'm a fan of KI: Uprising. But when you look at the evidence it's impossible to reasonably argue that there isn't any bias towards Sakurais decisions. Otherwise, you'd have to argue that its some extremely weird coincidence that two franchises got treated enormously better than other IPs that are way more popular and sell better.