Notes:

So, in case anyone doesn't know what is happening, basically a good chunk of the classic games are now gone with the new ROBLOX update because of the news about "ROBLOX Gang r--- exploit" (well, they are on experimental mode). Any classic game with the dev stop using ROBLOX will be gone forever, and some devs have to rescript their entire game just so that it can have "FilteringEnabled" into it.
FilteringEnabled is a thing that makes ROBLOX games secure against exploits and hacking (in-case that there isn't another accident in the news like that), and it is necessary so you can publish a ROBLOX game nowadays (you can only disable experimental mode if your game has FilteringEnabled), if you game doesn't have FilteringEnabled it automatically goes into experimental mode, where only the dev and his friends can play. So if the dev never returns to ROBLOX, the game is now officialy unplayable.
And further more, some classic games aren't supposed to have FilteringEnabled, if they have, it has a extremely high chance to break the game.
TL;DR: ROBLOX now makes every game that isn't FilteringEnabled into "experimental mode" (most of 2006-2013 games) because of the news about parents being angry about sexual exploits, you can't play "experimental mode" games unless you are a friend of the dev, so basically, you can't play them.
(Also if somehow you were friends with a dev… well… you still can't play because of the follower update, unless after the follower update you got to be a friend of the dev again)