No, my sister has hundreds of vacuum sealed plushies and they all return to normal when opened.

large pushies are often vacuum sealed before shipping overseas to minimize package space.

source: bought a 30cm plushie overseas in july

Depends on the type of stuffing. On a small, soft one like that, it's generally fine. Larger stiffer stuffed animals may have a styrofoam core, in which case it depends on the strength of the vacuum pump.

You're being downvoted but I was legitimately under that impression as well. Is it not actually the case??