There’s this website called scanurls.livetools.com that I found on this other Wayback Machine sequel. The “scanurls” website itself allowed you to find urls from all kinds of websites before Microsoft bought livetools.com and all the website’s other stuff were taken down. I typed in scratch.mit.edu and there was this bunch of urls that would redirect to a 403, image or even to a completely different ‘uploads’ website! There’s also scratch.mit.edu/js
which, at least should redirect to a 403 error, because, maintenance. But what does scratch.mit.edu/svgs/modal/close-x.svg have to do here? It’s just a blank page. And why does uploads.scratch.mit.edu need to have ‘/projects/thumbnails/(insert number here).png’ after the main url to work? And why does the page scratch.mit.edu/svgs/intro/hat-block.svg show something I’ve never seen on the Scratch website? And why does scratch.mit.edu/images/ideas/try-it-icon.svg say ‘Action Menu/Actions/Surprise’ in the tab name of the url?

There’s just so much to ask. And why don’t we continue to ask and expand our knowledge?

For scratch.mit.edu/svgs/modal/close-x.svg, that is NOT a blank page. It is a tiny (and white) X, which, as the URL suggests, is used in modals (windows).
For uploads, that is the server used for storing thumbnails/user icons! You aren't supposed to view its “front page”.
Why should scratch.mit.edu/js redirect to a 403?
scratch.mit.edu/images/ideas/try-it-icon.svg is probably a copy of the Surprise icon (in scratch-gui) to scratch-www. so it also has its tab title.
scratch.mit.edu/svgs/intro/hat-block.svg is used in the front page banner that appears while you're logged out: