It’s an interesting question. The RPIP states:
Eligibility
To be eligible for vote participation, the RPL must be effectively staked in the Rocket Pool protocol as reported by
getNodeEffectiveRPLStake().
At the time of the vote on RPIP-4 getNodeEffectiveRPLStake() reported RPL below 10% as effective and only cut off above 150%. The Atlas upgrade changed what getNodeEffectiveRPLStake() does. I think you could argue that RPIP-4 never intended to only count above 10%.
I also looked through the original discussion thread and could find nothing on this aspect of effective stake.