Before clicking in, I have to ask the question: are people upset because boobs were added or because they were reduced/removed?
Upset that they exist. Since the claim was you could count everyone upset on one hand out of the first hundred replies, I thought I'd look closer myself.
The top three replies shown to me are:
"It doesn't matter if the actor wanted her big boobed character to be in a plate bikini. This is still a sexual stereotype is hugely problematic within the hobby that should not be perpetuated in a show for children who will not get the 'joke' (Which is actually just sexist)." - I'd call that upset.
"Finally! A show for me, a white cisgender man who loves big boobs and sexism and btw is really tired of DnD being so "PC" these days if you catch my drift. Happy to see you guys back on track and creating the content I love" - I'd call that upset and sarcastic about it.
"Uh, y'know how you've had a few really good years because you made your game easier to get into and visible bc of streaming and open to all, and people feel welcome and excited about being a part of it? The titty puppet is like a bucket of cold water on ALL that." - Again, upset.
Two after that:
"Could you maybe rethink the bottom part of this image a bit? You know, since we are trying to be an inclusive and not purile and gross hobby?"
That's followed by one upset about something else - the Kuo-Toa player naming his character "Slippy Richardson" aka Slippery Dick (fish pun and sex pun simultaneously).
A few more down and at this point I'm just a bit over a dozen replies down and , umm, have more than 5 (around 7) that seem to be upset that a black woman given free reign to design her character as she saw fit and having a custom puppet made to match her description created a female character with large breasts and revealing outfit.
After that it seems about evenly split between people complaining about puppet boobs, people picking on people for being upset about puppet boobs, and finally some other more general commentary. And more people taking offense at Slippy Richardson, after having actually seen the show.
If you can only find 5 examples in the first hundred replies you really, really aren't paying attention.
I want to say it was Burning Crusade but they had major issues with how to assign and display leg and foot armour, mounts and a few other things.
See, my response to that would be to just not give them leg or foot slots, and then give them a racial bonus to bonuses given by equipment so that it washes out. After all, they moved to more standardized stat layouts on gear in BC so this would be a lot more manageable as opposed to in vanilla where there was a lot more "weird" gear.
This isn't really worth my time in looking up, so I'm just guessing at the "mentality" here: Puppet = Muppet = "for kids"; puppet + cleavage = trying to sexualize children's media
More D&D is supposed to be explicitly inclusive and diverse and boobs are sexist.