It would likely be temporary until we find a way to create more space and/or move to a synthetic medium.

In either case, it would be a choice. If you think people would choose living forever over having kids, you yourself are implying that people would find living forever more meaningful than having children, thus not "depriving them of the meaningful aspects of their lives," but rather, introducing something more meaningful: the ability to enjoy life without the Damocles Sword of death.

Bodily autonomy/choice ought to be a part of any society, and that includes dying when you choose to die. Who is anyone to tell an individual when they should die? The best we can do is give them the choice, as it's a deeply personal decision.