Rights are acquired and based on residences Edit
What this means is that once you've earned an ascension right, you can never lose it. It also means that it doesn't really matter how many people you have in your houses.
So while you will need to reach the limits of the different tiers to unlock the ability to ascend to a higher tier, once you've done that it stops looking at your actual residents and simply count the number of residences you have of each tier.
This opens up for some interesting meta gaming when it comes to ascension. For example, you can "pad" your island with empty Pioneer residences simply to gain ascension rights. You can even remove lower tier residences once you've acquired enough ascension rights of a certain tier, even before you've ascended them all.