In their 16th July 2020 developers update the development team provided an insight into the popularity of classes and sub classes.
The table provides an insight into what people prefer to play.
Much of the focus was on the fighter retaining the crown as the most popular class at 13%.
More is interesting to note is that 70% of all characters made do not fall into the classic dungeons and dragons classes (fighter, cleric, wizard, rogue). It highlights that adventure designers need to be cautious when building adventures that suit the classic party. Assumptions like access to dispel magic, knock, and comprehend languages to pass through encounter may not hold.
Undoubtabley someone will take fireball so designers can rest assured of that.