A TOS on a different page that you didn't present before sending any "content" such that there is an opportunity to either accept or reject the offer is not a contract. Contracts are not a "gotcha" that you can surprise people with nor are they established without an understanding by both parties of the obligations that would be created by a contract (the "meeting of the minds").

If you present reasonable[1] terms first, then receive some type of notification that the terms were accepted (as you say, signature is not the only option), only then will a contract formed that could obligate someone to not run an ad blocker.

[1] unconscionable or misleading terms are unacceptable and can get the contract - whole or in part - thrown out.