LOL!
I wish their CS had given me at least that information.
But they said it depends on the route...
I think your best option is to just book through their website. Then you can see the marketing title of the fare. I’d just like to explicitly search for upgradable fares on ITA Matrix... After recently being upgraded, I am addicted.

In Europe, we have nothing like that. You can be a LH HON Circle member, BAEC GGL member, any upgrades you receive would be entirely at the discretion of the staff. So receiving GUARANTEED upgrades is pretty amazing for me.