Eh, but then you'll have people who'll get impatient with spectating. Sure, you can die quick in S2, but not every player goes in and tries to splat everything and anything they see. You'll have people who like to retreat and play defensively and support others; squid parties are also a thing where no one else could get splated for the rest of the match, although squid parties are outliers usually.
In my opinion, they should go with spawning in bots to take a DC'd user's assets and program the object to paint the map and attempt the splat nearby opposition within a certain radius. It'll most likely be easy to splat, but atleast the disadvantaged team has something helping them out objectively.
While it certainly isn't a perfect solution that will please everybody involved 100% of the time, we're are dealing with a situation where you really can't please everybody 100% of the time, it's just inherent in the scenario.
Even in the scenario where an AI is slotted in, is that really helping? Other than putting up a facade that there are still 4 players on a team? Cause honestly, unless they make the AI really good, or cheat and has aim bot attached to it, the AI is probably not gonna perform anywhere near that of the player that did disconnect. I wouldn't enjoy it cause it just means one more blot of my enemies' team ink on the field every time they get splatted. Not to mention unless they make AI specifically tailored to ranked, their contributions will be non-existent, or even detrimental in the case of Splat Zones where their splat could be the difference between the enemy gaining control or not.
This AI solution might not be so bad in Turf Wars, since that mode is not entirely serious and the tides can change any moment. In Ranked, it is a whole other story because there is actually a rank on the line with each match. While the AI isn't necessarily hurting (unless its Splat Zones and the above happens), them being there isn't really making the uneven match anymore fair.
While certainly, the slotted out player might become discontent if they aren't being slotted in fast enough, a situation where they wouldn't be would only boil down to a few situations.
1. The other 3 players and the other team are all Squid partying, in which you were doomed already.
2. Two are squid partying and one guy is just god tier. I mean, props to that guy for not getting splatted, but that's kind of unlikely... The more likely situation is the 3rd guy is gonna get splatted petty quickly and then it's your turn and you two go on an endless cycle of doom.
3. Your team is winning and suppressing them. Which I mean, shouldn't really complain. Enjoy your power squad.
4. All three are being pushed playing defense and trying to stay alive for a prologues period to time. Yes, you contribution may help, but you're being kept out because your contribution would mean an unfair advantage. But let's be honestly, how often does this happen and nobody isn't being splatted like every 10 seconds?
But I mean, splats in most situations are not uncommon if the game is a stalemate or your are on the losing end. And if you are on a fabulous winning end, one should not really complain.
The suggestions was geared more towards maintaining a sense of fairness in situations where it matter more. Especially in Ranked, there is nothing more annoying than getting a crack because the game put you in an unfair 3v4 (DC only prevents losing your rank, but you can still get cracks to your meter). My suggestion remedies that by forcing the other team to play a 3v3 game, despite them having 4 players. Slotted in AI unless they were godly would not really have made that 3v4 situation any better in Ranked.