I've weirdly heard people say this in the past too and I am equally baffled.
I think it stems from the fact that Google was slow at making C++11 available internally so there was a period of time where the rest of the world was using smart pointers and we couldn't. That may have just solidified a "Google uses old C++" meme out in the wild despite it being wildly out of date.
I write C++ at Google, and it encourages use of modern C++ features, and many things you see adopted in std have roots in our libraries.
I'm curious what you think Google prevents us from using and why you think our C++ is like 90s Java.
https://abseil.io/tips has a lot of our philosophies and abseil is chunks of our internal libraries published externally.