Earlier quoted context omitted.
There is no reason to believe the current rate (about ~35,000 over the period 2010--2020) to change rapidly, so we are probably safe for this century. You should be aware that emoji gender and skin color is encoded in character sequences and modifiers rather than atomic characters, exactly in order to avoid that exponential growth. And in the unlikely case that Unicode gets so many characters somehow, you can always…
Ok but what about all the cryptocurrency symbols? Those will probably accelerate the rate. Perhaps not by a significant or even measurable amount. Nonetheless, it's a great reason to start investigating a blockchain alternative to Unicode
> Will Unicode be flooded with symbols for many crypto-currencies?
> Most other crypto-currencies have learned from the difficulty that a non-Unicode symbol causes for Bitcoin, and use a symbol already in Unicode. For instance, Dogecoin uses Đ, Ethereum uses Ξ, Litecoin uses Ł, Namecoin uses ℕ, Peercoin uses Ᵽ and Primecoin uses Ψ. Some, like Ripple, use Roman capital letters (XRP), mimicking ISO 4217 currency codes.
> While it is possible another crypto-currency will have a non-Unicode symbol that is extensively used in text, this is unlikely.
I think this section was crucial for the eventual acceptance, because Unicode people do care (a lot) about long-term consequences of proposals.