This summary is not the rule. The rule text controls.
A lawyer can join groups that work on changing laws or how laws are carried out, even if a client of that lawyer might be affected by those changes. Being active in law reform work is allowed, and lawyers don't have to avoid these groups just because their client has some stake in the outcome.
But there's one requirement. If the lawyer knows a decision the group is making could really help one of their clients, the lawyer has to tell the group about this. The lawyer doesn't have to say who the client is, just that a conflict of interest like this exists. This keeps things honest without forcing the lawyer to break client confidentiality.
The idea behind this rule is to let lawyers stay involved in public interest work and legal reform, since they often have useful knowledge to offer. At the same time, it makes sure the organization knows when a lawyer's advice or vote might be shaped by outside interests, so the group can make informed choices.