Yes, when my youngest dd was close to three I was asked twice for her ticket, once at MK and another time at AK. Both CM's were kind and respectful but I could tell the CM at AK wasn't sure if dd was truly 2 (she was) but let us through.
Fast forward to this past April 06 with my sil, neice and nephew. My neice was asked almost every time I think because she was walking in as my sil rented a stroller in the parks. The CM's asked her in kind fun sometimes silly way, how old are you cutie, big girl, minnie, princess etc. I was surprised as my neice is tiny barely 22 lbs and small and dosen't even look her age despite turning two next month.
Until recently its been kind of common knowledge that until recently WDW wasn't going to challenge a guest attempting to bring in a child over three without a ticket. For that reason I personally think that the CM's are now asking more and have more authority to ask for a ticket or proof if a child looks to be over three. IMHO its a benefit that has been abused and this may cause those with children who legitimately are two or under to be questioned. If my dd's were still under three I would probably bring a copy of the BC just in case.
TJ