@aaron-patten I agree with the majority of this, but I doubt that Chalice will ever be unrestricted. It makes for a miserable play experience, warps deck construction, and increases the importance of the die roll even more than the Sphere effects. As long as the DCI has a vested interest in Vintage as a competitive format, it is unlikely to come off the list.
It is sad but true. Chalice kept a balance on Moxen for many years and made it possible to justify skimping on off colour moxen which was a really great time for Vintage not just because the cost of play is so much of an issue in paper but also because the Moxen are restricted for a reason and they are still played in full in the vast majority of decks. Chalice changed that for a time and made a lot more decks viable in the process. It also acts as a counterpoint for the issue of the race to the bottom for which Mental Misstep is the last remaining bastion. Mental Misstep doesn't do as good of a job on it's own as when Chalice played a role as well since people have to Mental Misstep harder in order to push through. With both in the format you had multiple ways to punish opponents for going under while you buy a turn to go over the top making a sort of Vintage mid range strategy set viable. It was a far better time in Vintage for strategic diversity. I think it's important to have checks against the restricted list, especially moxen, so that the format can have more variation. But I definitely agree that it's unlikely Wizards will recognize this.
Other formats don't have moxen and people still play them so having cards that are decent against the moxen is not actually damaging to Vintage. The moxen are still good in the format even with Chalice. The real issue with Chalice is drawing multiples such that you can lock out their entire deck starting with one drops and then placing the second copy on 2 etc. It's a rare case but probably more important than Chalice 0 case and could be a reason that people would still need to pack sufficient main deck artifact removal for certain strategies (Storm, Elves, etc.). In my opinion it's a good thing for decks aiming to win on turn one to have to deal with significant disruption because that kind of strategy is often sighted as a barrier to entry into the format by players who are less familiar with Vintage. Vintage has had the reputation of being a blisteringly fast format for a long time and I think it scares away some new players. it's difficult to say which is more scary for new players between having four Chalice of the Void available or having games end on turn one.
Edit: There's also a distinction to draw between cards that help the format because they are good Against the restricted cards and cards that don't help the format because they are at least as good With the restricted cards. I think Chalice falls into category one while Workshop falls under category two.