Whatever happened to RailConstraints?

It seems like some developers are talking about this right now for some reason, so whatever happened to RailConstraints? Are they still being developed or have they been abandoned or put into some sort of limbo state, I’ve seen a similar question asked by the Super Bomb Survival / Find Everything developer Polyhex.

So where the heck are RailConstraints Roblox? I would like some sort of concrete answer from a Roblox admin who knows what the heck is going on with the features teased at RDC 2021.