When you freeze, they give you a PIN to unlock it. You can't unfreeze with just your hacked data alone. Of course, the PIN is probably in the next column over, so...
What do you want to bet it uses stuff like your SSN to verify?
[1] https://help.equifax.com/s/article/ka137000000DS9XAAW/What-d...
> Please provide proof of identification, such as a copy of your driver's license, passport, birth certificate or other proper identification forms.
Given that the hack included name, SSN, date of birth, and address, a fake copy of one of these should be incredibly easy to generate.
edit: Driver's license numbers were also leaked in some cases. Fun.
http://www.highprogrammer.com/alan/numbers/dl_us_shared.html