It’s primarily a media consumption device, it was already plenty strong enough for that purpose. Hence why it’s got an upgrade to an SoC from 2018 and not one of the other newer, more powerful models that have been released since. Of course they’re going to say it’s a significant boost, they want people to buy it. 
We’ll have to see, but there’s literally no evidence at present that Zwift will perform any better on it.