Of course, that’s just fan speculation based on the way the franchise has been progressing so far, but it’s definitely not out of the question that the developers might be planning some more interesting developments for its future.
The community of “Zelda” fans have been speculating actively with regards to every single game that’s come out in that series, and “Hyrule Warriors Legends” has been enjoying a lot of attention from the community as well. When a trailer for the game reportedly got leaked, this generated lots of discussions among fans and was a major story for quite a while.
That’s where fans saw the aforementioned crossbow as well, and it’s not yet known if it was an intentional move by the developers to drive up the hype for their game.
But then, if they wanted to do that, they could have easily released that information on their own and without resorting to cheap false leaks, something that gamers have generally grown to despise. Plus, we wouldn’t really associate moves like that with the developers of “Hyrule Warriors Legends”, as they are among the better studios on the market and have shown to care for their community deeply, including by always releasing information in appropriate ways and not messing with their fans too much.