Could it really all change in 1 day?

LO is 14 months old. Just one week ago was doing 2 naps perfectly as follows:

Wake: 6-6:30am
Nap 1: 9:30-10am
Nap 2: 1:30-3pm
Bedtime: 7pm

However, literally overnight, he’s been waking up at 5:30, then 5, and now 4:45, on the exact same schedule!!!

I understand there’s a drop to 1 nap around this age. But could the signs for that really just happen overnight? Or is there something else I should be addressing?

Thanks for all advice 🥰