With Madrid it always appear that they do make plans both for the short and long term because they believe they need such a squad in other for them to be sure about winning trophies in long term but with some others, the case has usually been different that they just want results for a particular season. It's going to be rare for Madrid to really have challenges withthe thei games in the new season because they have got a whole lot of strength that's unmatched with that of others who would want to compete.
Regarding Real Madrid building a short-term and long-term squad. Indeed, there is no doubt at all about Real Madrid, this team has a clear vision and mission in every season, especially in the long term. Some of this has been proven, such as last season by bringing in Joselu and Kepa on loan, of course only for the short term to fill the void of injured striker and goalkeeper Courtois. However, after the arrival of Mbappe and Endrick, the Real Madrid squad is certain to be an almost perfect long-term squad because all the players are talented young players.
Of course, looking at Real Madrid's current strength, it can be predicted that they will be able to defend the Laliga title next season, especially since Barcelona is currently unstable, plus with a new coach, of course Barcelona needs to adapt to a new coach, and this takes time. So as you said, maybe next season no team will be able to compete with Real Madrid, especially in the race for the Laliga trophy.