Guild Wars 2

Now, I know this might be a silly question, but..

Anyone knows, is there a chance that a Belinda’s greatsword will be up for grabs from the gem store?

We never know what is coming up, but we can see when the last time something came up thanks to the efforts of the posters in this thread:
https://forum-en.gw2archive.eu/forum/game/gw2/Gemstore-items-new-sales-discounted-prices

As you can see, the last time it was on the Gem Store was 7 months ago. As time goes by, the likelihood of it returning increases.

http://gw2timer.com/ now has an alert feature that will tell you when a specific item is on the gemstore; you may wish to avail yourself of that.