Yes, it exactly means you can put the psi weapon directly on hybrid soldiers.
As for having multiple special weapons (one on armor, one on soldier), one will take precedence according to the rules already in place for HWPs/aliens that you mind control:
- The order in which the items are loaded into the unit determine which shows for the icon - for your soldiers the one defined on armor is loaded first, so it will be the one shown on the icon.
- The order for special weapons accessed by an empty hand are done in order of the battleType for the item: Melee takes priority, next Psi amps, Firearms, Medikits, Motion scanners, then Mind probes last. If the two special weapons are the same battle type, then the load order determines which is used (armor first).
If you're going to use both in a mod, I'd recommend setting a convention for separating the two special weapons. For example, put the soldiers' one always in both empty hand and special icon, then armor only in special icon.