What is this trying to protect from? You see the actual URL in the tweet. Are you worried about redirects, if so why?
Additionally if I want to share a URL with friends it's usually polluted with all sorts of nonsense query parameters, this tool strips them and gives you a nice clean one.
As for the tracking element yeah, the link shortening services will still see my IP connecting to the service, doing a head request, just with a different user agent (whatever the one go's stdlib sets). One extra layer could be to move the go service out of the network, but tbh I didn't start this project with these considerations in mind
It only resolves the links navigated to, right? It shows you the interstitial page, but only when you try to navigate to the link.
It does enable you to get the clean link and share that.