Wow, surprised to see these this afternoon! Nobody asked, but here's my take on each of the new sets:
71753 (Fire Dragon): This looks like a solid dragon, although nothing super innovative here. I like the wing design. Shame that the minifigures are slightly disappointing, but I suppose that was expected.
71749 (4+ Bounty): Not much to say here, I'll definitely skip this one. Odd that they're sticking with Legacy 1 suits for the ninja here, would have been a good opportunity to get some more Legacy 3 suits.
71739 (USR): I agree with a lot of what's been said already that the squat appearance is a little shocking, but after getting over the initial differences it actually looks like a decent model. Most exciting here for me is the fact that the two villain minifigures have a good chance of being new Serpentine, seeing as they are solid white in the prelims and existing figures tend to be shown in full. Some signs point to them being Constrictai, including the trans-orange fang blade and catapult similar to that in the OG Samurai X Mech. However, they also don't seem to have short legs, so they really could be anything. As long as they aren't the same 3 snakes we've been getting for the last few years, I'll be happy.
71734 (4+ Blade Cycle): Nothing to say here, other than nice to see Rattla pop up again.
71756 (Bounty): I'll admit that I was a little skeptical of the Hydro-Bounty when the name first leaked, but I think they've done a good job here. The white color scheme is striking (although the lack of red is a little upsetting). I am definitely a fan of the mini subs dispersed throughout the sets, and with 6 of them I'm hopeful we'll see one for each ninja. The villain chariot is very cool and the return of the stingray element is a welcome sight!
71755 (Temple): This is definitely my favorite set of the wave so far. The giant snake/eel/monster looks really cool, and I like how spread out and open the temple is. I think a lot of people are disappointed in getting snake villains again, but I think it's nice that we now have matching fire and water snake tribes, right down to the giant snake creature. I'm intrigued by the figure floating in the middle with all the water effects... I wonder if it's going to be some sort of powered-up Nya? Because that would be amazing.
71754 (Water dragon): I'm just really happy we're finally getting a water dragon. I like the idea someone mentioned about Nya transforming into the dragon. It would certainly help differentiate this dragon from all the previous ones, story-wise, and might even be able to tie into the Akita lore from S11. I'm not yet sold on the wings, but I look forward to seeing this set from other angles.
71752 (Jay's car): Another obligatory ninja vehicle. I might pick this up, depending on price and the included minifigures. Could end up being a cheap army builder.
71750 (Lloyd's mech): The obligatory ninja mech. It's pretty small and doesn't seem to include anything noteworthy. I would have preferred these smallest two sets to feature villain vehicles, something that has been lacking recently, really since the Hunted subtheme all the way back in 2018.
Overall, I'm impressed with these sets, especially the larger S14/15 ones. Just how this subtheme compares to other recent ones will likely depend on the quality/distribution of the minifigures (please please please include all 6 ninja). For now, I'm very happy with what we're getting, and I'm excited to see the final products!