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?"