Verbier and Laax are closed in the summer. Verbier has fuck for a glacier.
Talking july-august...
France has Les 2 Alpes and Tignes. Don't go to Tignes for park, it will be melted away in August. Les 2 Alpes is excellent at that time, just very little snow, lots of rocks. But it's uncrowded, and the Les 2 Alpes summerpark matches Snowpark NZ in terms of size and features.
Switzerland is your best bet for august, you have Zermatt and Saas-Fee. Both have excellent parks, though small, but uncrowded, very expensive though. These parks are so high that the snow remains excellent in august, better than many winter parks in Europe, and they usually get fresh snow in August. However, if it storms, the glaciers are closed, it happens that the glacier is closed for 5 consecutive days.
Austria will have Hintertux and Kitzsteinhorn open with parks in August. But the low altitude of these glaciers combined with the lack of snow, I wouln't bet on it. Dachstein and Kaunertal are closed by then.