It bothers me that it always seems to be all or nothing in these sorts of things. Either the park only release a statement and copy/paste to all comers, or they spend an hour personally replying to everyone. I think the best answer, as always, lies somewhere in the middle. If I email them, saying I'm sad the wild mouse is gone, and all I get back is the same statement they've released, I'd feel a bit fobbed off and as though nobody there actually read my email, just saw the keyword "wild mouse", and ctrl-c, ctrl-v'ed their heart out.
However, if they spent 30 seconds "Dear Dar, I understand you're upset, we all are too, but [paraphrased press release]. Keep an out for what we've got planned!", seems a lot more personal and as if someone actually cares. They don't, but a human touch can go a long way to making people feel more comfortable.
As for the Mouse itself, I would have preferred it if they announced it was closing and then turned it into a bit of a museum for this season and then took it down a bit closer to when they're going to use it.