I think Djokvovic wants to find a sweet spot where he can play tournaments such that he can collect a lot of ATP points in order to stay 1st in the ranking, but also to not risk the rest of his career because of physical wear and tear. His focus will definitely be on the GS tournaments for that matter, but he is probably going to play most of the ATP 1000s as well. He is now playing a smaller tournament in Bosnia and if he wins it I think he can will stay at the top. Alcaraz won the Barcelona Open last year and would have to win again in order to not drop any ATP points.
That is part of my point, Djokovic with high confidance should come to Barcelona and make Alcaraz drop that points. There isn't many playera out there capable of winning against Alcaraz.
This move tells me that Djoković thinks he is not at his best now and decided to play smaller tournament to get some wins.