I looked at a 2023 black line on Thursday that had similar ( but way more) wetness on the front boot. Today when performing an oil change and coolant exchange I noticed mine was wet too. Is this normal?

 

... I would wipe it totally clean & dry and reinspect after some miles. Probably some minor weeping that is not an issue ... always looks worse when first discovered.

 

I wouldn't worry about it, something to watch with each oil change. If the kdss system is malfunctioning you'll notice it with regards to handling before any leak.
More important for longterm viability of the KDSS system is the keep the actuator valve body clean and rust free along the drive side frame rail (has a small skid plate protecting it). remove the skid plate and clean everything up and lube it with fluid film annually.

Lastly, it's a 2023 so you're under factory warranty if you're still concerned and it keeps seeping then take it to the dealer before your warranty expires in several years.

 

I'm sure they will tell me it's normal just like the leaking upper ball joints.

 

While I'm not one to defend dealerships ... until something leaks, breaks or ceases to work, weeping does not represent something where Lexus is liable. As to ball joints ... suspension ball joints are not hermitically sealed, so will originally ooze a superficial amount of grease ... this is normal.