Does the pledge amount get blocked or temporarily removed?

Does the pledge amount get removed from the address that registers the pool or does it get blocked?
The poolDeposit gets removed at registration but returns when you retire the stakepool.
I can still see the amount that was pledged.

Hello @ThaiTheo,
The pledge is not blocked or temporarily removed. Pledge is a pure promise, nothing else, it is not enforced in any way.

Of course, if you do not fulfil this promise, it has consequences: the pool will get no rewards. A pool that has no rewards will sooner or later lose its delegators.