Google Nest Wifi Router Offer

I should be receiving my Nest router and two additional points any day now. My question posed to the community is this: the tutorial says to hide SSID in the T-Mobile router. Is that just turning off the broadcast signals so you can't see them with your, phone, computer, tablet, etc. Or is it completely turning off each one all together? It seems if your able to go into the T-Mobile router and turn "off" the ability for the router to broadcast at all, the double Nat thing shouldn't be an issue, but this is really above my pay grade. Just trying to make the best of my use of my T-Mobile setup. Price and availability drove me to T-Mobile and recent tower upgrades have me seeing download speeds in th upper 300-400 mbps, but my upload speeds have been cut in half from about 50-60 mbps to 20-25 mbps. The value based on price and needs smokes my other two options of spectrum and Altafiber (formerly Cincinnati Bell).