Is it actually possible for them to keep adding content without raising the level cap

[Rizon]

As I understand it, the plan is to flesh out the game for the first year. That is what the 3 planned major updates are for. After that there will be a major expansion where there is a probability that the level cap will be raised.

[verily]

As I understand it, the plan is to flesh out the game for the first year. That is what the 3 planned major updates are for. After that there will be a major expansion where there is a probability that the level cap will be raised.

This is correct.