"small" things like this I assume end up really expensive in wills.
Making a page of text available to the public for 500 years might involve 25 people (each person being responsible for 20 years), and each of them has to be paid enough to care. To ensure each is paid enough, there needs to be a fund to pay them, and that itself needs to be managed by someone, who will also want paying for their troubles.
Also consider that in 25 generations it's pretty likely there'll be a major war, civilization collapse, change of monetary system, etc. To make such a scheme resistant to such things, you're probably going to need multiple people involved in every generation, all geographically separated, and all will need paying.
Even if you set aside $1M of your estate to this, I don't give it more than a 50/50 chance of survival.
I think it's harder than you might think. The New York Stock Exchange was founded in 1792 (229 years ago), there's a lot of things that can wrong over the course of 500 years to mean funding for your project would disappear. Wars, civil unrest, large environmental events etc. are all pretty much guaranteed over a 500 year time span.
According to this page https://finance.zacks.com/first-company-offered-new-york-sto... the first five stocks listed included the Bank of New York which still exists as BNY Mellon. It doesn't indicate what the other four stocks were, but presumably they no longer exist (The NYSE page on Wikipedia lists other traded securities as shares in The First Bank of the United States (defunct in 1821) and the Bank of North America (which became a private institution (it was previously the de facto central bank of the nascent U.S.) in 1785 before merging with Commercial Trust Company in 1923. Its successor institutions were eventually acquired by Wells Fargo so presumably if you'd bought shares in 1785 and held on to them for the next 236 years you'd now be holding shares in Wells Fargo). As far as I can tell all other trading was in government bonds.
Making a page of text available to the public for 500 years might involve 25 people (each person being responsible for 20 years), and each of them has to be paid enough to care. To ensure each is paid enough, there needs to be a fund to pay them, and that itself needs to be managed by someone, who will also want paying for their troubles.
Also consider that in 25 generations it's pretty likely there'll be a major war, civilization collapse, change of monetary system, etc. To make such a scheme resistant to such things, you're probably going to need multiple people involved in every generation, all geographically separated, and all will need paying.
Even if you set aside $1M of your estate to this, I don't give it more than a 50/50 chance of survival.