Are Bastion's "Equip Weapon <#>" controls non-functional?
Yes, the 1 and 2 are a mistake. Pressing 1 or 2 will never switch Bastion's weapon.
Bastion can only use one weapon in each of his configurations. There is no way to switch weapons except to change configuration.
You can find out how to change configuration a bit to the right of the screenshot in your post, according to your keybindings.