WotC's Jeremy Crawford talks about the way they are changing spellcasting monsters in D&D.
- Making the game more fun, easier to learn, shorting "the pathway to getting to your bliss".
- Making monsters easier to run.
- "Rumors of the death of spellcasting [in monsters] are not true". Innate spellcasting has been streamlined with spellcasting into a single trait.
- Spellcasting options are consolidated whenever possible.
- Removing options that a DM is unlikely ever to use.
- In some cases, new magical abilities in the monster statblock which exist alongside a list of spells they can cast.
- For example, the mind flayer's mind blast is not a spell, and other abilities are magical but not spells and aren't as easy to interact with with things like counterspell.
- Things which make archmages say "How is this functioning, and why can't I stop it?"