No, the POC only shows the script leaking memory into javascript running within the same process, and thus the same site. Chrome is still preventing the info from leaking across sites.
The big caveat to this is that an attacker can generally get a browser to include a cross-site resource in their process. For example, `<img src="https://sensitive.com/myprofilepic.png">` will cause the image to be loaded in the attacker's process where they can then potentially steal it. The article "Post-Spectre Web Development" goes into details on how sites can defend against this (and other vectors).