It isn't a necessity for plants to live in a cycled tank. After all, in a cycled tank the plants would be competing against ammonia with the bacteria. All plants need to thrive is light, nutrients, and some water movement would help (to help move the nutrients along the water column and for gas exchange). Many NPT tanks have no filters. just a powerhead/bubbler. How do you think people kept fish during the few centuries before we could harness the power of electricity? :P
Actually some NPT tank owners say that the only care they put into their tanks is the trimming of plants, topping off evaporated water, and a partial water change every SIX months.