When it comes to Announcement post, I think it would be nice to create tournament on Lichess more than 1 hour before start and create Announcement post when tournament is already created so You can put link in post from the start.
I think most people are simply checking "newest" posts in tags interesting to them. If they see the link, some of them will click it. If they see the post without link, they will browse other posts and when the link will be put in the post, the post will be hidden under a lot of newer posts and people will not come back to it.
The same think may correspond to reminder posts in spanish/russian/polish You want us to make. They would be better if the link to tournament will be inside them as they are new posts.

Of course I'm not a Steemit expert, this is only my private thought without any proof.
Best regards.