I fully expect to see the "Nationals" script on their primary home jersey fairly soon. I have no inside information, this is just pure speculation on my part, but they've been slowly bringing it into the spotlight.
In 2017 they introduced their current BP/practice jersey, the first time the script appeared on an on-field jersey:
Then in 2018 they introduced the navy alternate, first time the script appeared on a jersey that was used during a game.
And obviously the prior mentioned ST jersey, which they totally could've seen as a prototype kinda thing.