Sarah's tweet went viral for making the claim that Wiz and Angular are merging. A lot of people may not even know what Wiz is. Wiz is Google's internal frontend framework. It is focused on high performance and hence it is basically a mixture of vanilla javascript, freemarker like templating and so on. Angular on other hand is much more enterprise ready framework.

Sarah's message is probably incorrect. Wiz and Angular are not merging to become a super framework of any kind. Wiz is pretty much internal to Google and is unlikely to find much adaption outside of Google. It is unlikely to be open source and based on the publicly available sources, there are no plans to "Actually merge" both.

What Sarah's means here is that Wiz and Angular both will see some modifications to each other so Wiz can use Angular and Angular can use Wiz. Basically better interoperability.