I think it says a lot more about the fact that them losing the game was a foregone conclusion. Discord had no intention of letting them win (see his corruption of Fluttershy). I'd wager the elements weren't even in the garden, and he did the whole thing just so that the Elements of Harmony wouldn't ever be summoned, because their bearers wouldn't be attuned to them anymore.
Basically, when Discord hypnotizes the pony, they lose all affinity with their Element. At this point, it's hard to say Dash is even going off to save Cloudsdale. She's acting entirely in her own interest and it's hard to say finishing the game or saving Cloudsdale are consistent with that. If the Wonderbolts hail from Cloudsdale, I'd say it's more likely she's going there to make sure there is still a Wonderbolts squad for her to join.
Discord would know that removing Dash's affinity with her element, then offering her her wings back would ensure that he wins the game. It's a situation where it's impossible for the mane 6 to win. Ultimately, you can't say Dash lost the game for everypony. She was just the most valuable piece for Discord to capture, and he had the board rigged so he could capture her.