Is this paradise meant to be perfect? It won't be boring or meaningless, because that would mean that it's not perfect.
Also, change can be pleasurable and as such not automatically contradicts paradise imho.
I got into a discussion about this on the TheGoodPlace subreddit before I left. You've hit the nail on the head there - it's not possible for you to get bored, listless, frustrated, unfulfilled, etc. in a perfect paradise, because then it wouldn't be perfect. If you're imagining those effects, then the paradise you're imagining isn't a perfect one, and so is irrelevant to discussions about a perfect one.
A slightly more interesting discussion is "I, as I am now, dislike the thought of becoming a pleasure-zombie in the future. It makes me uncomfortable now to consider being motivationless and content in the future" - which, sure, fine, ok. Sounds like internalized protestant work ethic to me ("I don't deserve to be happy unless I'm working hard, and I only know that I'm working hard if I'm miserable"), but at least it's not logically irrelevant like the first argument.
The most interesting version is "I don't see a continuous line of consciousness between me and the hypothetical-future-me who lives in bliss, so there's no reason for me to be concerned with their fate - they're not really me" - which is pretty subjective depending on your views of continuity of identity.
