I have a tub of Gulp Alive minnows I haven’t opened yet and also a couple zip lock bags of Gulp minnows that are a few years old. Can I dump the ziplock Gulp minnows into the Gulp Alive? 
 

Regular gulp can go in the gulp alive containers no problem. I do that regularly with mine when fishing inshore. 

Do they still make Gulp? I assumed Gulp Alive was like 'gen 2' and just Gulp was older.

Gulp Alive is the same formula as regular gulp.  The only distinction is the FW/SW formula. 

You can dump old Gulp baits into the jar and recharge them, but unlike the older fishmeal formula, once the new ones dry out, they will not regain the correct texture/size when saturated.

Elaztech and elaztech like baits will actually absorb some of that liquid into the material.  It washes out fast in comparison to the gulp plastic formula.