All cards have randomized pins and can later be changed.

no, some cards you choose the PIN from the start and never get a randomized PIN

some banks some place in the world might make it a policy not to set PINs but to force random, you can't definitively say what you are saying, rather we can only go by what he said.

Nothing in this sentence

> One of my credit unions gives out (randomized) five digit pins (although they say if you use an atm that only accepts four digit pins, the first four is enough).

says that the PIN on that card can't be changed.