I don't think if it's a good sign for ethereum or not, but I see that the ethereum is on the green price and now, the price increase. I think in 2019, we will see many other banks in the worlds trying to use the different platforms and not just using ethereum as their network but also they will try to implement with the other coins. But lets we see what will happen with the Brazilian National Social Development Bank, and if there is a benefit for the bank itself, the other bank will come to the crypto.
We can say that it is a positive sign for ethereum because if a governmental organization or a bigger institution will come to start their token on ethereum platform then all of that community will come to know about etherum and among them there will be many investors who after knowing about ethereum will also invest in ethereum.