Academically? I take it she’s reading Peppa Pig in Latin, then.
For the record, my dd2 only gave up the dummy for good when she was coming up to 6. Her teeth have always been perfect (she’s now early 40s).
Dd1 OTOH was still sucking her thumb after she learned to drive! And yes, her teeth were affected to a small extent.
As for potty training, I do agree that it often seems to happen ludicrously late nowadays, but that’s IMO largely because nobody (or hardly anybody) has to wash nappies anymore. Also, a lot more children are in nurseries where the staff just won’t have time to do much in that department.
I spent a week each potty training mine when they were just gone 2, and it worked, but it was pretty much a full time, eagle-eyed job - which as a then SAHM I could easily manage.
OP, I definitely wouldn’t say anything - however well meant, it’ll probably only cause trouble.