I am sure this is just part of the growing awareness of the people on bitcoin. To be included in the new words of the scrabble game, the word has to be popular already and in use especially in online interactions. There is no doubt this can be helping for the mainstream adoption but of course there is no magic bean here. Certainly, the road to mainstream adoption is not just one event but rather a compounding effect of so many factors and even personalities contributing towards that goal. And of course, we are not there yet.
I am sure that scrabble addicts will get to know more of the word 'bitcoin' while they are playing the game. ~~~
Not only scrabble addicts but scribble players around the world. As rightly said by OP, my believe towards this positive news is that, it will drive adoption of Bitcoin to the masses.This move is in favor of the cryptocurrency community and in no time from now we will experience a greater adoption.