I don't think they're reinventing anything. Google Fonts has been offering webfonts for many years. All they did here was change the website.
They've changed their "typeface rendering engine" (for want a better description). Hence why many people are now unable to see their typefaces in full when once they could.
Not every browser on Ubuntu 16.04: Firefox displays those boxes but Vivaldi, Opera and Chromium work fine.
Google might have fixed some of the issues now - it was a day ago many of the bug were raised.
Just for reference, I was running ArchLinux with the Infinality font bungles.
I don't get the point of this. I really don't. While far from perfect, web fonts have largely been a solved problem for a while now, so why are Google reinventing this wheel? This seems to happen all the time with the web; people taking old ideas and reinventing them again and again, in yet more bloated ways, breaking things for millions.
</grumpy rant>