It's a big data centre.

But is it big enough to store 50 years worth of encrypted transmissions?

Far cheaper to simply have spies infiltrate the ~3 companies that hold the keys to 98% of internet traffic.

Of everyone's? No. But enough to store the signal messages of the President, down a couple of levels? I hope so. After I'm dead, I hope the messages between the President, his cabinet, and their immediate contacts that weren't previously accessible get released to historians.