Not unless you actually meant 16<x<18 today and >18 tomorrow.

You can be 30 and verify >16 today and >18 tomorrow, obviously without being 18.

which is nothing in comparison to leaking all of personal information

you can also introduce some jitter like changing age range only once a week/month/year for everyone

If you want privacy you need to fuzz the transition. Many platforms support that today. Or you can create a separate account when you graduate.

But also, knowing someone's birthday without trying it to other information greatly reduces the risk of harm.