It’s true that the official Amazon features are not proactive. Nor is there text to speech support. But you can ask Alexa what’s on your calendar, which is nice.
If you want to go further than that, you can use the fact that echo can be a streaming Bluetooth device and play notifications on it that you have set up on a different device, like your android phone. A number of people in the community have done that, and there are other threads about it.
( you’ll see in the following thread that initially I didn’t think it would work, but the guys made it happen. 
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You can also check into AskAlexa, I can’t remember if that does proactive stuff or not.
http://thingsthataresmart.wiki/index.php?title=Ask_Alexa
So right now if you’re willing to have a separate device to be the brains and just use the voice assistant as the voice, you can get this functionality from an echo, because the echo can also be a Bluetooth speaker. But I don’t think that’s available on Google home yet.
I do expect that all the voice assistants will add an official TTS feature in 2017, it will be interesting to see which one does so first. 