This indeed is a good news for every website owner, not just for WordPress, because now Google is piloting a new ad code type to improve latency of web pages with AdSense ads. This is a huge deal because it means that pages in your site will load faster, which also means a better experience for your readers. The new code, known as “asynchronous tag”, make sure that the web page loads to users, even if ads are having problem loading.
At the time writing this post, the new asynchronous tag is a beta feature in AdSense, as such Google says that moving to the new version is optional. This also suggests that the search giant may be planning to make this feature a standard in the future.
If you want to try the new ad code, you can create a new ad, the same way you’ve been doing it for years, but now you’ll also see a “Code type” menu, from this menu, choose “Asynchronous (BETA)”. Finally, grab and paste the code in your WordPress template, and you are good to go.
Google also recommends that if you’re thinking of trying this new feature to improve your site load speed, you have to change all the AdSense ad units in the page in order to see the difference.
For more information check this Google Developer Blog post.