I think it looks really fun. The characters look older, definitely softer but I think that fits for where they probably are in life as parents of teens. It's cartoony and stylized, but I think the key elements of each design have been retained enough to keep that thru-line through it all. I could see these characters meshing into a Puss in Boots 3 pretty easily.
I like how scruffy Donkey is, and the bags under both his and Shrek's eyes. I think Fiona looks great, and so does Felicia's older look. The OG style is very much attached to its' place in 90s / 2000s pop culture, and is also inseperable from the past decade of memes. I understand them wanting to create somewhat of a clean break here.
I also don't get the criticism of referencing TikTok or the Shrek memes. The franchise has always leaned heavily into pop culture references and parody, and as long as it's limited within the film itself, I think lampshading the past 15 years of Shrek memes is definitely a solid way to reintroduce the Shrek world to the big screen.
Definitely excited to see more from this one!