In a community council thread last month, Blizzard revealed the intent of making the ‘follow’ action only available to be performed by using hardware input. This change makes it so addons can’t make your character follow another in reply to a whisper, for instance.
This is likely part of anti-boosting measures that Blizzard started applying to discourage boosting in Classic. It is important to note that this is not intended to reduce WoW’s accessibility.
