Google Messages can be the native texting app on your Samsung Galaxy S21. Which means the app is being allowed to replace Samsung Messages as the default.
Samsung revealed this detail during its Unpacked event earlier this morning. However it did not say that Google Messages would be the default messaging option right out of the box. This probably means that you can install Google Messages from the Play Store and have it become the native text app on the Galaxy S21.
But it won't be the default option immediately. That makes sense given Samsung probably still wants people to use Samsung Messages as the native option. While also not restricting people from changing things if they want to.
Availability of Google Messages on the Galaxy S21 may vary by country
While Samsung has made strides to ensure that Google Messages is native on its latest device, that doesn't mean it'll be available everywhere.
Samsung makes it clear that Google Messages availability on its new series of phones will vary by country. Furthermore it could also vary by region or carrier too. Which likely means not all carriers in all regions will be able to set Google Messages as the default.
This probably has to do with availability of Google Messages itself. Since it has to be downloaded from Google Play. And it would stand to reason that it wouldn't be allowed to be the default messages app if it wasn't available in certain countries.
Either way, if you're not a fan of Samsung Messages, try installing Google Messages once you get your new Galaxy S21.
RCS will be supported and Duo calls can be flung to your TV
Samsung confirmed during Unpacked that RCS features will be supported with Google Messages on the Galaxy S21.
One of the cooler features though is the ability to fling Duo video calls to your TV. Samsung explains that on the Galaxy S21, you can start a video call and the mirror it to your TV while still using the front-facing camera on the device.
This way you don't need a camera attached to your TV but you can still see the person you're calling on a bigger display.
Of course you will need a Samsung TV with Miracast on it or a Samsung TV that was launched last year. Either will work, allowing you to connect the Duo call to your TV wirelessly for added convenience.