It won't change states until you tell it to. The change states only occur on a configured manual action (i.e. someone selected the dropdown action to change state) or upon update of an asset if there is an automatic state change configured according to certain criteria and those criteria are met.

For example of an automatic transfer would be on a transition between the submitted state and another state if you configured that policy must run and the policy must return success then the transition will be taken upon update of the asset.

If the transition is only configured for manual action (which is the default) then it is required that someone explicitly does the action or it will in the state.

Lifecycles have a workflow defined for them. It is the workflow that defines what states are available. There are a  limited number of workflows available. Multiple lifecycles can share the same workflow.

So if you created a new lifecycle in original community but is based on the same workflow that implicit is based upon then when you move the asset back into the community (assuming that the new lifecycle is a better match then the implicit lifecycle) it won't change state unless you have an automatic transition from submitted to another state configured.

Also you must configure lifecycle match conditions and priorities. If the implicit lifecycle is listed first in the list of lifecycles for a community and there are no restrictions (conditions) placed on the usage of the implicit lifecycle (such as asset type) then the implicit lifecycle would always be the best match lifecycle and an asset would never move to any of the other lifecycles.