Looks like we may soon be getting more things to buy using samples and requisition slips. The Catalog Expansion has no cost, and buying it does nothing. The Upgrade Effect text must be null for Catalog Expansion, that field just shows the effect for whichever upgrade was previously selected.
Edit: It's been acknowledged on the official Discord, looks like it's unintended:
ALERT: ROGUE ITEM DETECTED. The Ministry of Truth has confirmation that a rogue item called the "catalog expansion" is temporarily visible in the Ship Management menu and, in accordance with regulations, we instruct all Helldivers to avoid this rogue item until further notice. The Ministry of Truth cannot confirm the reliability or safety of this item, nor can they confirm its origin.
I play on difficulty 7 and agree with everything you said. My typical load out for any of the 40 minute bug missions is typically: Rover, Quasar, Eagle 500kg, Orbital Rail Cannon. If I have to close bug holes, I'll switch the 500kg for the Air Strike. I've also been messing with changing out the Orbital Rail Cannon for the Autocannon Sentry, just because the cooldown is so long (like you mentioned).
If you've gotta kill 2 Bile Titans and 3 Chargers at once, which is pretty common, the Orbital Rail Cannon only does so much.