True, it's not the same as hashing a password and comparing hashes - you need to decrypt your data.
Encryption adds one layer of obfuscation for a bad actor that might steal the database but does not get their hands on the key. Plus access to the key can be managed differently than access to the database.
Either way, it comes down to sensitivity of the predictions made and how users would react should they be exposed before their due dates.
VDFs are designed to take a long time to compute. To use them here, it would require someone to be computing the solution continuously between the time the prediction is made and the time it is revealed - that's too inefficient for this purpose.
Encryption adds one layer of obfuscation for a bad actor that might steal the database but does not get their hands on the key. Plus access to the key can be managed differently than access to the database.
Either way, it comes down to sensitivity of the predictions made and how users would react should they be exposed before their due dates.