I think we should take out Keith Thurman now as there's not even a bit of fresh, updated, and recent news about him. It's like before that he is not active and may be on hiatus again. Even prior to the sudden news about this rumored fight between Terrence Crawford and Errol Spence (I say rumored, as no official announcement yet), anything about Thurman is out of the news.
Back to the topic, yes we should expect the official announcement on this fight on April 22 as stated when this news came out. Maybe after the fight between Ryan Garcia and Tank Davis, an update will be followed.
The June 17 date can't be considered as the official date without the official announcement. It was not yet a done deal until it was announced officially.
Thurman's camp behavior is in conflict with what they always do when they have a fight, they have the fight to sell but they are quiet, all camps are quiet on this issue, Crawford, Spence, and Thurman camps I think they all agreed that they will not to talk to media until the official announcement, I'm sure Thurman is compensated to fave a way to a Crawford - Spence fight and I'm sure whoever wins the match he will be the first challenger, which is a good opportunity for him because he will be challenging for an undisputed title.
It's better to be quiet if there's no assurance that the fight will happen. I'm pretty sure they are being more careful now to not disappoint the fans, as the Spence vs Crawford fight was highly hyped earlier this year. Once the deal is finalized, if there is one, then it wouldn't be hard to sell the rights since both boxers are popular. It's a big fight that fans are eagerly anticipating to watch.