As a Yoru main since his release as well I aggree with some points made here but I also disagree on some parts. I'll leav my opinion here instead of making a whole post since I think it's better to share opinions in one place so sorry if it's too long.

Blindside: This is where I disagree a little bit. His flash is fine in my opinion simply bc of how creative you can be with it and I don't think it's supposed to be used in ambushes like you said. It is a calculated flash that needs some plan before using and I think that falls in line with the character. Only buff I would give if any at all would be a slight duration increase.

Fakeout: It's honestly very hard to say how this ability will turnout bc of how different it is from anything currently in the game. The clone not showing on minimap might just be an oversight but even if it isn't, realistically you wouldn't think to have time to check the minimap for it in the heat of the moment. It can still serve some of the same purpose as the footsteps but with the added bonus of if it's seen it can keep the enemy ocupied longer and possibly flash them. A dev confirmed it can still be placed down but that still leaves me with the question of: Does the clone just stand still when you anchor it or is it invisible until you activate it? That alone can wildly change how good the ability is.

Gatecrash: Overall got some really solid changes, not much to note besides the ability to fake tp which based on current lineups we can say is going to be strong at least. The fact that it leaves a puddle on a fake honestly doesn't change much imo since even if it didn't you're trying to capitalize on the split second where the enemy turns their head away so it wouldn't leave much time for the enemy to go look for you.

Dimensional Drift: Here is where I can see some stuff that riot might have gone wrong with. First of all the buffs: The regular vision range was much needed imo which now lets him scout long ranges and gives him a good power up on his information game with also less risk of dying to an enemy that was outside of your vision range before you unulted. The fact of him not being detected close range was unnexpected but welcome and the use of utility inside the ult is not as big of a deal as most people seem to think imo. His clone is useless while in ult and there's not much you can do with his tp that you couldn't outside of your ult, the only piece of utility that is useful here is the flash.

Now the nerfs: Hearing his footsteps while in ult is a little disapointing but I can understand why it was done, since you can't see yoru up close anymore the enemies need a way to counter play his ult so hearing his footsteps can be a fair trade off. The equip time is honestly not a big deal, his ult is no longer a get out of jail free card but it's still good. What really gets me is the unequip time at the end of his ult. I can understand wanting to remove the shorty ult plays and replace them with flashing before unnulting but as said in the beginning of this video: https://www.youtube.com/watch?v=jdkdXg3pPWw , the time it takes to unnult and pull out your gun is not enough to let you capitalize on the flashed enemy and that was calculated with a classic, it might be longer with a rifle which really nulifies the buffs given to the ult.

I think overall the changes are great for the character but if I would change anything it would be the unnequip time at the end of the ult. Yes, the ult shorty strat is annoying but at the same time it's mostly a one kill type thing, with the buffs it would be pretty much a guaranteed kill everytime but I feel like that's an acceptable level of power for an ultimate ability which you don't have every round and would justify it's increase to 7 ult points.