There is indeed no limitation on the number of tokens in a game.

There are many combo wins that involve having (technically) infinite tokens, dealing infinite damage, gaining infinite life, taking infinite turns. You get the idea.

I said technically because in practice, setting this to a very large number is enough for the win. Dealing 1e6 damage is, although possible, already way overkill in most cases when your opponent starts with 20 life.

Though you do need to pick a number. The paper itself describes a game state which devolves into the 'the player who picks a larger number wins', and even gaining a large but finite amount of life can be dangerous if you don't go large enough (I have heard of a specific example of someone gaining arbitrary life, picking a google, and then losing by have their life reduced to zero through a series of losses of half their life).